Successful Thai EFL Students and their Language Learning Strategies for Acquiring English If Clause

The fact that English if clause is too difficult does not entail impossibility for EFL students to master it. In the Thai context, a few have managed to use it correctly despite persistent failure among many. The present study principally aimed to find out how successful Thai EFL students learned to acquire this grammatical structure by virtue of the language learning strategies (LLS). A group of 32 university English majors were individually given an oral test in which different types of if clause were under investigation, and afterwards a questionnaire to complete about their application of the strategies. Findings show an overall poor performance with only seven students passing the test. Mismatch between verb forms and meaning constituted the general typology of mistakes hypothetically as a consequence of negative mother tongue transfer, as well as a lack of deep understanding and acquisition of the structures that was supposed to be internalized. Regarding LLSs, the use of mental pictures was found to be significant – successful and less successful students applied it differently ( p = 0.029) – hence the probable strategy that helps with their acquisition of the structures. Pedagogical guidelines for incorporating the LLSs into an EFL classroom were provided.


Introduction
One of the most difficult grammatical structures in English is if clause.It is even hard for the native speakers (Celce-Murcia and Larsen-Freeman, 1999).
Inherently, if clauses mete out a somewhat high level of form-and-meaning relationship complexity to their users.An if clause sentence, composed of if and result parts, requires the specific formation of verb formulae for both parts, and these formulae can vary depending on the shades of meaning the speaker intends to give.To illustrate its challenge, this sentence is taken as an example.I would have promoted John to the position if I were the manager.The verbal forms used deviate the typical reference to time: the if part states the present, not the past, counter-fact that I am not currently the manager, and the second part the past counter-fact that I did not promote John.Moreover, the if part can be expressed in an alternative way using inversion, were I the manager, which sounds more confusing when the operative word if is removed.
The degree of difficulty of English if clause seems to be greater for learners of English as a foreign language mainly due to the syntactic discrepancies between English and their native tongue (e.g., Chou, 2000;Jones and Waller, 2011;Ko, 2013;Lai-Chun, 2005).Thai EFL students are no exception whose acquisition of this grammatical structure is problematic.They have always been reported with a poor ability in both comprehension and production (Katip and Gampper, 2016;Pengpanich, 2014;Suteerapongsit and Pongpairoj, 2020;Yossatorn et al., 2022), and their mistakes are sometimes deemed to have reached fossilization where no amounts of study can assist (Hinnon, 2015;Sattayatham and Honsa, 2007).Broadly speaking, their general mistakes stem from incorrect verb formation and mismatch between verb patterns and meaning.The cause of the former problem is in large part due to negative transfer of their mother tongue and of the latter problem a deprivation of internalized acquisition.Despite this, two decades of my English teaching experience confirms the existence of those who have managed to succeed in using English if clause, albeit in a much smaller quantity than those who failed.Hence, the key question is: How did successful Thai students learn to acquire English if clause?
Research to date has documented certain sets of characteristics successful students generally have or attempt to have.These include a combination of traits in both concrete and more abstract forms, such as a solid foundation of cognitive ability, positive mentality and effective learning style.As Rubin (1975) best concluded, "good language learning is said to depend on at least three variables: aptitude, motivation and opportunity" (p.42).Among the noted characteristics is employment of language learning strategies (LLSs), which have been reported to contribute to EFL students' better achievement whether it involves the acquisition of general or specific skills of the language (e.g., Al-Adwani, 2017;Gerami and Baighlou, 2011;Graham, 1997;O'Malley and Chamot, 1990;Rubin, 1987Rubin, , 1994;;Tabatabaei and Hoseini, 2014).In this regard, Rubin believed that the good learner employs certain techniques to acquire knowledge and this makes them successful.Scholars maintain that LLSs not only enhance students to progress in their learning (Ellis, 1994) and make it more enjoyable, self-directed and transferable to new situations (Oxford, 1990), but help instructors to conduct more effective lessons and build better learning environments (Lessard-Clouston, 1997).Previous study has extensively investigated a selection of LLSs made by successful and/or unsuccessful EFL students when they tried to learn the different aspects of English (e.g., Nguyen and Terry, 2017;Rahimi and Riazi, 2005;Sartika et al., 2019;Tamada, 1996), their effects on EFL students' overall English proficiency (e.g., Al-Adwani, 2017;Alfian, 2016;Gerami and Baighlou, 2011;Lee and Heinz, 2016), their relation to student autonomy (Chen and Pan, 2015;Daflizar et al., 2022), and even their impacts on the acquisition of a third language (Dmintreko, 2016).Notwithstanding a continuous series of past research, investigations of LLSs with respect to specific language tasks are in scarcity.In the most recent open-ended survey study titled Revisiting LLS research 40 years later by Cohen and Griffiths (2015), prominent EFL expert Mirosɫaw Pawlak strongly recommended "the focus [which] would be on areas that have thus far been neglected in research, namely grammar, pronunciation, and pragmatics "pragmatics" (p.416).
His urge has however hitherto not been satisfied with adequate empirical studies.The present study with the aim to examine what LLSs successful Thai EFL students applied in order to effectively acquire English if clause would not only fill the gap but, I hope, could inform a pedagogy that helps improve their performance.This can perhaps be applied in any EFL contexts similar to Thailand.To do so, an oral test was firstly administered to participants to examine how well they used the sentence structures and afterwards a questionnaire on application of LLSs was completed by them to see whether there were any significant differences between successful and less successful students.One point needs to clarified in the first place: an oral test was chosen, rather than a written one, since the oral test requires more spontaneity to perform and as such would give more concrete results.The following three questions were used as a methodological framework for the study, the last of which was the key.
1) To what extent did Thai EFL students use English if clause correctly in speaking?
2) In case of the errors committed, what were their typological characteristics?
3) Were there any significant differences in applying LLSs between successful and less successful students with respect to their acquisition of English if clause?

English if clause
To emphasize, mastering English if clause is a challenge.First and foremost, its verb patterns are various and complicated.Traditionally there are three types, namely future, present and past (Murphy, 1994;O'Keefe et al., 2007;Quirk and Greenbaum, 1973), or four when habitual, general or scientific truth conditions separate from the first type and earn their own, known as the zero type (Cowan 2008;Eastwood, 1994;Yule, 1998) There are some points to note.First, the result part can initiate the sentence as shown in example (iii), and in this way, a comma is not needed to set it off from the if part.Next, both parts require specific verb concordance, such as in example (ii), where the past simple is in the if part and the past form of future in the result part and in example (iii), where the past perfect is in the if part and the past form of future perfect in the result part.As can be seen from the last two examples, the verbs in if clause are generally "backshifted" to convey meanings of unreal events (Quirk et al., 1985(Quirk et al., , p. 1010)).This way of using verbs is perplexing for it does not preserve the typical usage of time reference.Past verbs are employed to describe very improbable or impossible events in the present, and past perfect verbs for unreal past events.Even more challenging is the possibility for mixed verb patterns as well as a use of different modal verbs depending on the meaning intended, such as If I were you, I might have reconsidered moving abroad, and You could have saved a lot of money if you'd bought an economical car.Last, subject-operator inversion can be applied in order to make conditional sentences sound more formal.The inverted version of example (iii) is You'd have saved a lot of money had you bought an economical car.
As for its meaning, English if clause has a myriad of nuances.Quirk et al. (1985) explained that if clause may be either an open or a hypothetical condition, where the former "leave[s] unresolved the question of the fulfilment or nonfulfillment of the condition," and the latter conveys the speaker's belief that the condition cannot be fulfilled and hence "the probable or certain falsity of the proposition expressed by the matrix [i.e.result] clause" (p.1091).From the above illustration, example (i) is an open condition since the sentence leaves unresolved whether Tim meets the lady, and so it leaves whether he asks for her number.Examples (ii) and (iii) are hypothetical conditions, for the result parts cannot be fulfilled contingent on the conditions which are by no means met: since I am and will never be you, I will not move abroad; and since you did not save much money, you did not buy an economical car.Moreover, Celce-Murcia and Larsen-Freeman (1999) created a different taxonomy of English if clause which reflected its different layers of meaning.They divided it into three types, each of which has subcategories.Since their work is more detailed and is often quoted in the literature, a brief space here is dedicated to their account.According to them (1999, pp. 548-552), type one is referred to as factual conditionals and has four subtypes: generic truths, habitual truths, implicit inference and explicit inference, where the first subtype requires the present form of verbs, and the rest the present and past forms of verbs with a use of different modal verbs, such as can and must, depending on degrees of inference.Type two is known as future (or predictive) conditionals and has two subtypes: strong condition and result and weakened result, where the first subtype uses the present form of verb in the if part and will or be going to in the result part, and for the second subtype, weaker modals, such as may, should and might, are used in the result part.The last type is imaginative conditionals and has two subtypes: hypothetical conditionals and counterfactual conditionals, where the difference lies in that the former is used to describe a very unlikely yet possible event to happen in the present or in the past, and the latter an event which is contrary to the fact.The verbs in type three if clause are always backshifted.
To sum up, English if clause is difficult due to the complexity in both its various forms and respective meanings.

Thai EFL learners' problems in acquiring English if clause
Thai is a non-inflected language, meaning that it has only one form of verbs.If I had come late, I might have missed the match.Three points are of note.First, as aforementioned, Thai verbs do not change their forms as shown by the verb come in all of the examples.Second, the three examples illustrate no specific verb concordance for Thai if clause sentences unlike those in English.The present form of verb and will in example (iv) are used in the if and result parts respectively for the present hypothetical condition; the present form of verb and might in example (v) in the if and result parts for the future condition; and the present form of verb and might in example (vi) in the if and result parts for the past hypothetical condition.Last, subjects can be omitted in Thai as shown in examples (iv) and (vi), where I is needed in the correct English translation.
With these huge cross-language syntactic discrepancies, more effective teaching and learning are required in order for Thai EFL students to use English if clause correctly and fluently.To be more exact, deep understanding together with strategic practice is perhaps the only way to help them internalize the structure in question.However, the most prevalent teaching methodology in Thai EFL classrooms is rote-learning where memory plays an overwhelmingly major role and practice is kept to a minimum.When English if clause is taught to them, ready-to-use verb patterns are always given without critical explanations for the complex relationship between their structures and meaning.If he comes, I will go; If he came, I would go; and If he had come, I would have gone, are the incantations they are usually given.The problem is also aggravated by assessment methods which do not aim to test their ability to use it, but mostly to recall the sentence structures memorized.According to reports, Thai EFL students either fail to inflect verbs into the correct form or choose the correct pattern for the intended conditional meaning.As for the former mistake, it appears that mother tongue interference has adverse effects on their production of English if clause, especially types two and three which require the backshifted verbs (Suraprajit, 2022;Yossatorn et al., 2022).The following sentence is a common example illustrating their failure to inflect the verb into the correct form.
*If Jane see you in the morning, she may invite you to the party.For more able Thai learners, misselection of the verb patterns still persists (Katip, 2015;Katip and Gampper, 2016;Sattayatham and Honsa, 2007).This is often the case where present and past forms of verb are incorrectly used in place of past and past perfect forms of verbs needed for counterfactual events; for instance, *If I am you, I will give it a try now and *If I studied harder, I would pass the test.
To conclude from the second language acquisition perspective, Thai EFL learners' mistakes derive from both interlingual and intralingual factors with the former caused by negative transfer of their mother tongue and the latter by a lack of deep and natural understanding.EFL students of other languages with no verb inflection systems, such as Chinese, are reported to have experienced the same difficulty (Chou, 2000).

Language learning strategies
Over the past three decades, language learning strategies (LLSs) have been a topic of interest among EFL scholars primarily as a consequence of the gradual yet significant shift from the emphasis on teachers to learners and learning, coupled with their empirical effects on student achievement.Personally, I find it very fortunate that EFL has eventually taken this direction since it is indeed more of the student's responsibility than of the teacher's to set out on the language-learning journey in order to succeed.Albeit very important, teachers are merely facilitators for the learning.Practically, once a student equips themselves with LLSs, they become learners of autonomy (Benson and Voller, 1997;Oxford, 1990) -the learners who are always disciplined, motivated and reflective for their own learning and so would guarantee themselves a chance to succeed, at least at a higher degree than dependent learners (Oxford, 1996).
The term LLS has been defined in various ways yet holds the similar concept of the student's own plan and implementation of that plan in learning a new language.While some scholars refer this action in an abstract viewpoint to acquisition of special thoughts and behavior (O' Malley and Chamot, 1993;Richards and Platt, 1992) or mental steps and operations (Wenden, 1991), others define it as application of particular learning methods and activities (Cook, 2016;Griffiths, 2007;Rubin, 1987).In either case, LLSs prioritize the freedom and determination students have in developing their language competence in L2.Among the notable scholars, Oxford gave a most precise and comprehensive definition of LLS as follows: specific actions, behaviours, steps, or techniques that students (often intentionally) use to improve their progress in developing L2 skills.These strategies can facilitate the internalization, storage, retrieval, or use of the new language.Strategies are tools for the self-directed involvement necessary for developing communicative ability (1992/1993, p. 18).
Oxford went further to make a distinction between direct and indirect strategies in her Strategy Inventory of Language Learning (SILL), where the former refers to learners' mental processing of the target language using memory, cognitive and compensation strategies while the latter refers to learner's learning the language without directly involving it, using metacognitive, affective and social strategies.Memory strategies include creating mental linkage, applying images and sound, reviewing, employing actions; cognitive strategies include practicing, analyzing and reasoning; and compensation strategies include guessing and overcoming communication problems.Metacognitive strategies involve centering, planning and evaluating the learning; affective strategies involve controlling feeling and emotions; and social strategies involve interacting with others.

Participants
Since I had noticed considerable mistakes my students committed while using English if clause during their discussion and presentation in class, my current students from Pragmatics and Introduction to Literature classes were the subject of this study.Student participation was on a voluntary basis with the parameters of the study explained to them beforehand.A consent form was signed by those willing to participate in the study.Finally, there were 32 participants, all of whom were Thai nationals aged between 18 and 21, were English majors whose language proficiency was between intermediate and advanced and reported with no hearing or speaking impairment.All of them had completed the English program's fundamental course English Structure, in which if clause was a key component, in addition to their reports of former study of the sentence structure during high school.

Instruments
There were two instruments: an oral test and a questionnaire.The oral test assessed participants' spontaneous performance in using English if clause and, if any, gathered mistakes they made.An individual participant was asked ten questions about concepts of environmentalism (see Appendix A).This familiar topic was chosen so as to prevent their speculation that English if clause was being tested, which otherwise might have affected their genuine performance.The first two questions asked about their current study situations and the rest about the set topic.Of all the questions, six questions were asked using an if clause structure and so a response using the same sentence structure was expected in reply.Each type of if clause had two questions: items 2 and 6 for type I, items 4 and 5 for type II and items 8 and 9 for type III.The other questions were distractors.
The questionnaire was adapted from Oxford's 1990 Strategy Inventory of Language Learning (SILL).Even though there is a new version of SILL (Oxford, 2017), the original version was considered to better serve the present study's principal purpose to examine the differences in employment of the LLSs between successful and less successful Thai students, regardless of any specific contexts of the learners -the critical dimension the newer version takes into account and posits that the learner's self-regulation is of paramount importance to their success.Even though it is more dynamic and intricate, it goes beyond the scope of the present study.The questionnaire comprised two sections: demographic data and questionnaire items (see Appendix B).The first section asked about their gender, current year of study, overseas experience, and English proficiency.The second section contained 28 Likert-scale items asking participants to rate the extent to which they had applied LLSs in order to learn English if clause.Five groups of the strategies were included in this questionnaire: memory strategies (items 1-6), cognitive strategies (items 7-11), metacognitive strategies (items 12-18), affective strategies (items 19-24) and social strategies (items 25-28).The original compensation group was excluded because its strategies about guessing meaning from context and overcoming communication problems were not related to the study.

Procedure for data collection and analysis
On the test day, the individual students and I met face to face.After explaining the test details, I began to ask each of the questions and have them respond freely.A self-made check form was used to assess their performance during the test.The form was in table format where the first column contained the ten questions, the second column their answers with a special attention to if clause sentence structures to be written out, the third column a yes-no tick for accuracy of the grammatical structures used in their answers and the final column any remarks to make.After the oral test, each student was given the questionnaire paper.During this time, clarification was given if they found any items unclear and the paper was submitted once completed.
After all the participants had completed the test and the questionnaire, the check forms were analyzed in greater depth.The if clause sentences which were used by individual participants were sorted out into either correct or not correct based on the accurate relationship between the form and meaning of the if clause sentence they produced.The correct sentence gained one point and the incorrect one gained no points.In three types of if clause which had two questions each, participants who had at least one correct if clause sentence in all types were considered successful and those who had no correct sentence in each of the three types were considered less successful.In case where the sentences contained no if clause structures, they were not analyzed.Scores from the test were used to distinguish the successful participants from the less successful ones.The overall scores were also presented into frequency as well as percentage to account for the accuracy rate of each if clause type.When mistakes appeared, the typology of mistakes was created and explanations for the possible causes were to be provided.Then, all the students' scores from the questionnaire were summed up and calculated into means and standard deviation to show the extent to which participants applied each of the five groups of LLSs for the acquisition of English if clause.Finally, in order to make a comparison, a t-test was used to examine the differences in applying LLSs between successful and less successful students.The p value was set at < 0.05.It is imperative to note that demographic data were not treated as independent variables in the present study, which, if so, could have yielded any other significant findings.

Thai EFL students' performance on English if clause
On the whole, participants had quite a low ability in producing English if clause sentences while speaking.Even though almost all of them produced type I if clause sentences correctly, about half and three-fourths produced type II and type III if clause sentences incorrectly, respectively.The most common mistakes involved the mismatch of verb formulae and their meaning.The Table 1 below summarizes the number and percentage of the successful participants in each type.In type I of English if clause, only one from 32 students had incorrect production of the sentence structure two times (questions 2 and 6 from Appendix A).Among all the students who used it correctly, two had it one time incorrect.The most commonly employed structure was I plus will.Seven students chose to use would to indicate a degree of less certainty, which was considered correct.In type II, 11 out of 18 students correctly produced two if clause sentences to both questions (questions 4 and 5 from Appendix A).As for the mistakes committed, the present form of verbs was used instead of the past form of verbs.The type III if clause was the most challenging with 24 students using it incorrectly.Only one from eight correct students correctly used it two times (questions 8 and 9 from Appendix A).I would and I will plus a bare infinitive were mistakenly used in place of I would have plus a past participle.When taking all the three types together, only seven students were assessed successful.One student who was successful in producing type III if clause sentences made incorrect sentences in type II.These findings are in line with a series of past research revealing the difficulty most Thai EFL students have in producing English if clause sentences especially those with the meaning of hypothetical condition (Katip, 2015;Katip and Gampper, 2016;Sattayatham and Honsa, 2007;Yossatorn et al., 2022).This long-standing problem implies the ineffectiveness of teaching this English grammatical structure in Thai EFL classrooms, or students' lack of effective learning strategies to deal with it, or both.

Typology of mistakes
On a deeper level, the mistakes participants committed when orally producing English if clause sentences identified some underlying causes of the problem.They are seen to have experienced a lack of profound understanding as well as natural awareness of the very complex natures of English if clause structures whose verb patterns and their time reference do not conform to the typical usage.The more the sentence gets structurally complicated, the more participants are likely to be less successful.The following Table 2 lists the general mistakes found in each if clause type followed by detailed explanations.

If clause type I
As can be seen in Table 1, this type of if clause did not pose a problem to participants.Only one of them produced the targeted structure incorrectly.The common verbal forms they used were I will and I would.The former structure is more familiar for them when they studied English conditionals in school, and it is also the structure used in the questions asked: What will you do if you run into the problems with your studies?and What will you do if the Faculty asks for your cooperation in saving energy such as electricity and water?The use of I would by seven students is of particular interest since it is not assumedly the familiar form.This suggests a higher level of understanding which allows them to use a mix of verb concordance in the if and result parts.Given the only one mistake, the less successful student's answers to question number 2 "Read by myself" and question number 6 "I not use conditioner" indicate her general low performance in English language rather than specifically in the sentence structure under investigation.The subject and the modal verb were also incorrectly omitted.

If clause type II
The common mistakes in this type were the verbs which were not backshifted.Almost all the less successful students used the auxiliary will in their answer to the two questions: What would happen if the world had no trees at all? and If you were the prime minister, what would you do to help the environment?This time they did not even seem to notice the tested structure used in the questions.
Examples of the incorrect sentences are "It will not be lively and very hot," "There will be less oxygen," "All living things will die," "I'll move the capital city," "I'll have policy to grow trees" and "I'll regulate the big companies".Occasionally, there was a use of the present form of verbs, such as "Human cannot live" and "It is the end of the world".Participants' selection of the mentioned verb forms suggests two interesting facts.First, they tended to use the more familiar verbs they had studied: would is less frequently taught and used than will in Thai EFL classrooms.Last, they tended to understand the questions and give an answer without taking the English syntactic structures into consideration, hence failing to acknowledge the role of English past forms of verbs which are used to state present hypothetical conditions in English if clause.Linguistically speaking, the sole intention to access the meaning of sentences overshadows attention to their syntactic rules.This kind of error can then be considered intralingual in the way that their understanding of the inverse relationship between form and meaning of English conditionals is not yet complete, let aside internalized.Also, the error is interlingual since such features in English does not exist in Thai and so some participants directly transferred Thai syntactic rules to produce this type of English if clause sentence.

If clause type III
A large number of mistakes in this type confirmed participants' failure to deal with the inherent complexities of English if clause.Since this type is formed from a more complicated verbal structure, their spontaneous production was inferiorly inaccurate, even though the intended meaning of their produced sentences was well understood.Like those in type II, their verbs were not backshifted or sometimes not backshifted enough.Will and would were the most common auxiliary verbs less successful students used in their response to the questions: What would you have done if you had seen your friend wasting things such as food or energy?and What could you have done when you were little if you had realized the impacts of global warming before?Incorrect sentences include "I'll educate them," "I will talk to them it is not good," "I'm going to advise and give a solution," "I might ignore it," "I would tell them to stop," "I would tell them to do the right thing" and "I would try to be more selective using stuffs".This kind of error is more of intralingual nature since the mistakes reflect participants' inability to use a compound of auxiliary verbs (would + have + a past participle).Their use of would + a bare infinitive indicates a certain level of knowledge.From the foreign language acquisition perspective, their closer attention to the meaning than to the syntactic structure of if clause sentences puts certain issues in the forefront.First, they had difficulty with and then failed to internalize the structures of English conditionals which are removed from those in their native tongue.Second, due to the syntactic complexities, students chose to ignore them and focused solely on meaning for communicative purposes, a linguistic act which is inappropriate for learning a heavy verb-inflection system like English.Last, the current approach to teaching this language topic may therefore be deemed not effective enough.
To summarize, participants' mistakes were both interlingual and intralingual.The Thai syntactic rules occasionally played a negative role in their inaccurate production of English if clause sentences while speaking.A very few participants failed to inflect English verbs.More appositely, the complete and/or profound knowledge of the language topic was seen to be lacking since most participants chose wrong verb patterns for the corresponding conditional meaning.The verbs they used were not backshifted for unreal situations, a solution to which very special treatment is needed so that correct production can be made naturally and fluently.

LLSs applied by successful and less successful Thai EFL students
The oral test identified 7 successful students and 25 less successful students.To remind, success was counted when there was at least one correct if clause sentence from each type in the individual participant's response.The following Table 3 shows the important statistics about application of LLSs for learning English if clause in each category by both groups.Successful students applied LLSs more than less successful students except those in the affective and social strategy categories.When taking a closer look, there were two specific techniques the two groups of students applied differently at a significant level, namely creating a mental picture of a situation in which English if clause might be used (p = 0.029), and encouraging oneself to use English if clause despite fear of making mistakes (p = 0.040).The first technique is in the memory category and it alone was powerful enough to make the whole category significant (p = 0.048).The second technique is in the affective category but did not make the whole strategy group significantly different between both groups.Based on the findings, both techniques of creating mental pictures and self-encouragement might have played an important role in their process of internalizing the acquisition of English if clause.At least, this imagination strategy gave them more chance to practice freely and extensively at their convenience.Scholars have acknowledged the pivotal role of imagination in language learning (Egan, 2005;Norton, 2001), and more importantly in motivating learners to learn the language successfully (Dörnyei, 2009).Recounting my own experience when I was an English-majoring student, I also used the imagination strategy to tackle English conditionals.I often created imaginary situations where I practiced the sentences alone outside class.I had more practice and gained more confidence with my English ability than my classmates who relied solely on the knowledge and practice in class.

Conclusion
In direct response to the three research questions of the study, findings have revealed 1) an overall poor performance in orally producing English if clause sentences by the participants, 2) the verbs which were not backshifted for type II and III if clause as their general mistakes, and 3) a significant difference in applying certain LLSs between successful and less successful students.The first set of findings confirms the tremendous difficulty of English if clause experienced by Thai EFL students as also reported by previous research (Suraprajit, 2022;Yossatorn et al., 2022;Suteerapongsit and Pongpairoj, 2020;Katip and Gampper, 2016;Hinnon, 2015;Pengpanich, 2014), and even to a greater extent when they had to produce it spontaneously while speaking.Second, the fact that the mistakes were generally intralingual in nature indicates a certain level of knowledge about this English grammatical structure possessed by the participants although it is yet incomplete.The use of would plus a bare infinitive for type III if clause is a strong evidence for their developmental stages of learning and using the structure in question.This in turn suggests a possible room for improvement or even perfection if more effective methods of teaching and learning are introduced to them.Last, the fact that seven participants from the present study were successful lends possible values of LLSs in the way that they give students an efficient apparatus with which they can have more time and direct their own ways to tackle the complexities of English if clause, which is not permissible in a normal class where time is limited and the teacher usually directs learning.The strategy of creating mental pictures in particular provides them with overwhelming time, freedom and assurance by which they can practice the targeted language task anytime and anywhere.This is to some extent in accordance with Rubin's belief that the good language learner takes and creates opportunities to practice what he has learned while the poorer learner passively does what is assigned to him (1975, p. 44).To be more precise, once the student imagines situations where they are to apply English if clause sentence structures that they have learned in class, they automatically create their own opportunity in which to practice their language skills in a free and motivating way.Hence, the more they employ imagination for practice, the more they become inventive (Manolescu, 2023) and motivated toward learning (Lanonne, 2001).
Indeed, these findings suggest both challenges and work to be done in order for the student to overcome the failure and for the teacher to assist them to acquire English conditional sentences in a more effective way.Definitely, both of them need to cooperate to complete this enterprise.There are two specific tasks: linguistic competence drills and practical application of LLSs.Given the former, spelling out the cross-syntactic differences in the conditional sentences between English and their mother tongues should be a good starting point by which students are to be consciously taught to attend to the recognizable and more subtle linguistic differences as well as the complexities of English if clause especially types II and III where verbs are backshifted.To meet this end, a variety of teaching formats and activities are needed.A series of receptive skills drills should be given to students where they are immensely exposed to the different types of English conditional sentences in authentic materials as well as trained to correctly identify their form and function as well as the mistakes and finally assessed of their understanding through various test types, for example, paraphrase, reading comprehension and error recognition.Besides, based on the small number of successful participants, the ability in producing the sentences is seen to be a greater challenge particularly while speaking, so a series of extensive productive skills drills is indispensable too.The problem might be fixed by the teacher having their students do controlled exercises where they are obliged to write and speak the different types of English conditional sentences on a given topic simultaneously.This exercise will not only help consolidate their understanding but increase their actual competence.
As for the strategies, LLSs which are teachable (Ellis and Sinclair, 1989;Oxford et al., 1990;Rubin and Thompson, 1994) should be formally introduced to students, especially with a focus on the mental picture technique according to the findings.When in class, the teacher explains what the strategies are and how they are applied with concrete examples.Students practice them in class and are encouraged to continue to use them at their convenience.In class again after some time, the teacher should make a follow-up of how students have been applying the techniques, that is, how they have formed a mental picture of situations where they used English if clause sentences and how effective it was, the latter point of which should be assessed by formal productive tests.By now, there should be a sharing of application of the strategies between successful and less successful students, and this mutual learning might help minimize the gap between the two groups.In a word, LLSs should be guaranteed a secure place both inside and outside classrooms as an apparatus to help individual students learn to the fullest.
Last but not least, the present study's small number of subjects and the non-treatment of such variables as gender and overseas experience were fully acknowledged as a major limitation, and as such a further study with more participants as well as other methods used to collect data such as longitudinal observations and experimental intervention would be very much appreciated to verify and/or generalize the present findings of this pioneering work.

*Author Contributions
Planning and conducting the test and the questionnaire; analyzing data; concluding and discussing data; writing a draft; revising the draft.

*Conflict of Interest
The author declares no conflict of interest.

Hearing impairment
. Below are examples of the three types in order.i.If Tim meets that lady, he might ask for her number.ii.If I were you, I'd reconsider moving abroad.iii.You'd have saved a lot of money if you'd bought an economical car.
Tense and aspects which are present in English, such as present, past, simple, continuous and perfect, can be indicated in Thai only by recourse to particles or situational contexts.For example, the word กำ �ลั ง [kāmlāŋ] signals a continuous event and จะ [tɕà] a future event.The Thai word equivalent to English if is ถ้ � [tʰâ:].Might good if he come to the party tonight.It might be good if he comes to the party tonight.vi.ถ้ ามาสายคงต้ องอดดู การแข่ งขั น 5. x̄(page 136) 6. type (page 136) 7. The part "Journal of English Education ….." sho which is in the line above (page 138) 8.It should be a full stop mark (.) instead of a comm 9.There should be a space between the full stop ma 10.The part "Ramkhamheang University Journal … which is in the line above (page 140) 11.It should be a full stop mark (.) instead of a com ด้ วย **If come late, might miss the match.

Table 1 .
Thai EFL students' performance on English if clause.

Table 3 .
Application of LLSs by Thai EFL students.

Section 2 Application of Language Learning Strategies Instructions:
□ No □ Yes 6. English proficiency level (scores of standardized tests may be provided) The table below is adapted from Oxford's Strategy Inventory of Language Learning (SILL) (1990).Please tick only one out of five options which best matches your agreement with the statements.l = Never or almost never true of me 2 = Usually not true of me 3 = Somewhat true of me 4 = Usually true of me 5 = Always or almost always true of me relationships between what I already know and the new things I learn in English conditional sentences.2 I use English conditional sentences in a sentence so I can remember.3 I remember English conditional sentences by making a mental picture of a situation in which this sentence structure might be used.4 I use flashcards to remember English conditional sentences.5 I physically act out English conditional sentences.6 I review lessons on English conditional sentences often.Part B: Cognitive Strategies 7 I say or write English conditional sentences several times.8 I try to use English conditional sentences like native English speakers.9 I use English conditional sentences I have studied in different ways.10 I write notes, messages, letters, or reports in English conditional sentences.11 I find the meaning of an English conditional sentence by dividing it into parts that I understand.Part C: Metacognitive Strategies 12 I try to find as many ways as I can to use English conditional sentences.13 I notice my mistakes in English conditional sentences and use that information to help me do better.14 I pay attention when someone is using English conditional sentences.15 I try to find out how to use English conditional sentences better.16 I plan my schedule so I will have enough time to study English conditional sentences.17 I have clear goals for improving my use of English conditional sentences.18 I think about my progress in learning English conditional sentences.

Part D: Affective Strategies 19
I try to relax whenever I feel afraid of using English conditional sentences.20Iencouragemyselfto use English conditional sentences even when I am afraid of making a mistake.21Igive myself a reward or treat when I do well in using English conditional sentences.22 I notice if I am tense or nervous when I am studying or using English conditional sentences.23 I write down my feelings about studying or using English conditional sentences in a language learning diary.24 I talk to someone else about how I feel when I am learning English conditional sentences.Part E: Social Strategies 25 If I do not understand something in English conditional sentences, I ask the other person to slow down or say it again.26 I ask English speakers to correct me when I use English conditional sentences.27 I practice English conditional sentences with other students.28 I ask for help with English conditional sentences from English speakers.