Introduction

At the beginning of the year, teachers have to design diagnostic tests generally in grammar to assess learners and evaluate their performance. They spend much time and effort in doing so, but most of them don’t make use of the information obtained from these tests to target problems and set appropriate solutions. Possibly, it seems for them as an obligatory task for administrative purposes rather than being a tool for bettering education or simply because of the lack of knowledge and skills to do so. However, educational diagnostic testing is of a paramount significance as it is one of the most efficient strategies to improve instruction and help teachers to determine the learners’ difficulties and tailor teaching to their needs. Hence, this work is an attempt to find out how data obtained from diagnostic grammar tests should be examined, interpreted and used to improve instruction and support students’ grammar learning. One of the most useful approaches that have been proposed for educational diagnostic assessment is error analysis, which focuses on the types of errors the student commits and their possible sources. The results of diagnostic tests together with error analysis can be successfully used in planning the suitable remedial teaching.

In spite of the collaboration of too much effort to improve English learning in general and its grammar in particular in Algerian schools, results are not satisfactory. What is remarkable is greater weakness of grammar competence mainly among high school pupils. One of the problematic aspects in English grammar among those learners is tenses. Hence, exploring the difficulties in using tenses has been taken as a case study in the current research.

Thus, this research work is conducted through applying a diagnostic test for the purpose of determining the learners’ difficulties in such grammar point through finding out the common types of errors committed by them in using tenses, the most common sources of such errors and suggesting some practical solutions to avoid or at least reduce them. This helps a lot in preparing instructional material for remedial teaching and planning the subsequent lessons.

1. Theoretical Background

1.1. Diagnostic testing

Testing is an efficient means to mirror the effectiveness of teaching or guide teaching to its effectiveness as in the case of educational diagnosis. The effectiveness of diagnostic testing as one of the most beneficial and necessary assessments has a paramount role in adjusting teaching for the purpose of improving the quality of teaching and learning.

Diagnostic testing is usually done at the beginning of the year, or before a term or course starts to identify the students’ individual strengths, weaknesses, knowledge, skills and their needs in a particular area to be taken into account in the planning of the lessons. More broadly, Akdeniz (2016) states that “the diagnostic assessments continue throughout the learning process whenever the teacher needs to identify an attribute or pre-requisite learning for a new content” (2016, p. 49). It can be conducted through the use of different methods, techniques and tools such as observation, student portfolios, questionnaires, question-answer, attitude scales, interviews, etc (Akdeniz, 2016. P.49). However, the most effective tool can be tests.

Diagnostic tests are characterized by some features that make them different from the other types of tests. Alderson (2005) lists a set of hypothetical features of diagnostic tests, from which we mention some of the most important ones.

1. Diagnostic tests are designed to identify strengths and weaknesses in a learner’s knowledge and use of knowledge.

2. Diagnostic tests are more likely to focus on weaknesses than on strengths.

3. Diagnostic tests should lead to remediation in further instruction.

4. Diagnostic tests should enable a detailed analysis and report on responses to items and tasks.

5. Diagnostic tests thus give detailed feedback which can be acted upon.

6. Diagnostic tests provide immediate results, or results as little delayed as possible after test taking.

7. Diagnostic tests are based on content which can be covered in instruction, or which will be covered shortly.

8. Diagnostic tests are likely to be less ‘authentic’ than proficiency or other types of tests.

9. Diagnostic tests are more likely to be discrete-point than integrative, or more focused on specific elements than on global abilities.

10. Diagnostic tests are more likely to focus on language than on language skills. (Alderson et al, 2015, pp. 44-45)

One of the main stands of diagnostic tests is a detailed analysis and report on responses to items and tasks as mentioned above. Hence, the data obtained from diagnostic tests should be analyzed in a well-organized way to achieve the purposes they are used for. One of the approaches that have been proposed for educational diagnostic testing is error analysis method. So, error analysis provides a way on how data obtained from these tests should be examined and interpreted.

1.2. Error analysis

For a long time, errors were considered as indications of failure. However, they are no longer considered so as a completely different opinion. On the contrary, they have been considered as an indicator of their learning process and as a device to improve learning (Corder, 1974, as cited in AbiSamra, 2003, P. 6). Before highlighting some concepts related to the theoretical background of this method, it is important to shed light on the difference between the terms error and mistake because many people often use them synonymously and interchangeably in spite of their considerable differences.

1.2.1. Error and mistake

The terms error and mistake are considered by many people as synonymous terminologies, but in fact they are different from each other. The distinction between them relies on the ability of self-correction. It is known as the self- correctability criterion as called by Corder (1971) and James (1998) (as cited in AbiSamra, 2003, p. 4). Snow (1996) distinguishes between errors and mistakes in three areas ; the first area is the presence of errors which the learner does not recognize as errors, the second area is the presence of errors which the learner recognizes as errors but which s/he cannot correct and the third area as mistakes which the learner can correct (Snow, 1996, as cited in Nzama, 2010, P. 44). However, Harmer (2007, p. 96) uses them as a broad term that refers to three categories ; slips that are mistakes which learners can correct themselves when noticing them, errors that are mistakes which pupils cannot recognize as errors and cannot correct themselves and attempts that are mistakes which pupils make when they attempt to do something but they do not know how. In this way, errors occur as a result of incomplete knowledge of the second language rules and mistakes occur as a result of some factors as inattention or tiredness and which can be self-corrected when drawing learners’ attention to them.

1.2.2. Error analysis background

The occurrence of mistakes and errors among EFL learners during the process of developing their language is an expected and usual part of language learning as a completely different opinion has occurred to consider learners’ errors as an indicator of their learning process and as a device to improve learning (Corder, 1974, as cited in AbiSamra, 2003, P. 6).

In the field of analyzing errors that language learners make, there have been two major approaches ; Contrastive Analysis (CA) and Error Analysis (EA). (Keshavarz, 1999, p. 11). Kim (2001) stated that through CA method, errors that learners make can be predicted by comparing the linguistic differences between the mother tongue and the target language (as cited in Heydari and Bagheri, 2012, p. 1583). However, there are many errors which did not result from L1 habits transfer, there were many others that appeared during the process of learning which had no relation with L1 (Ellis, 1994, P. 19). Therefore, it was replaced by EA by the early 1970’s because of its inaccuracy and the high criticism that it received (kim, 2001, as cited in Heydari and Bagheri, 2012, p. 1583). Error analysis has been described as “a set of procedures for identifying, describing, and explaining learners’ errors” (Ellis and Barkhuizen, 2005, p. 51). This explanation involves mainly identifying the sources of such errors to suggest appropriate solutions.

1.2.3. Error analysis models

Concerning models of error analysis, Corder as the founder of this new trend, sets a model. According to Ellis, his model involves the following steps :

1. Collection of a sample of learner language

2. Identification of errors

3. Description of errors

4. Explanation of errors

5. Evaluating errors (Ellis, 1994, p. 48)

Many researchers worked on Corder’ s model such as Brown (1994) and Ellis (1995) (Dodigovic, 2005, P. 178). Some of them such as Hubbard et al (1996) and Ellis (1997) provided clear examples of how to conduct such studies. However, Gass and Selinker (1994) identified six steps followed in conducting an error analysis ; collecting data, identifying errors, classifying errors, quantifying errors, analyzing source of error and remediating for errors (AbiSamra, 2003, P. 7). Hence, the ultimate aim of error analysis is to make use of the information obtained from the study to target problems and set appropriate solutions.

1.2.4. Error analysis and Grammar

Grammar is considered as the most essential aspect of language learning for second language learners. In order to be able to use a language properly, it is necessary to master its grammar. Many researchers argue the necessity of grammar instruction to improve learners’ accuracy and proficiency (Skehan, 1991, Ellis, 1994 ; 2002, Lightbown & Spada, 1999 as cited in Nonkukhethhong, 2013, p. 118). That is why, error analysis mainly focuses on grammatical errors (Hasyim, 2002, p. 42). In the process of foreign language learning, making errors mainly grammatical errors is common and something unavoidable. Some researchers referred the occurrence of errors to the lack of grammatical knowledge. Cook (2001) mentioned that no-one could produce a single sentence of English without having English grammar in their minds and the lack of a proper amount of grammar in the learners’ minds might be a root cause of the mistakes and errors committed by L2 learners (Cook, 2001, P. 26, as cited in Mourssi, 2013, P. 250). Thus, knowing more about pupils’ grammar knowledge helps a lot in improving their grammar competence. This has been proved by many researches which have confirmed that emphasizing on learners’ errors is an effective means to improve grammatical accuracy (White et al, 1991 ; Carroll and Swain, 1993, as cited in Hourani, 2008, p. 6).

1.2.5. Sources of errors

Identifying the sources of errors is an important stage in error analysis procedures. Several studies have been conducted to suggest different reasons why errors occur, in which the one done by Richards (1971) may be the first and most important (Heydari and Bagheri, 2012, 1584). Richards (1971) distinguished between three sources of errors ; interference errors, intralingual errors and developmental errors. First, interference errors result from the use of elements from the native language when speaking or writing another. Second, intralingual errors reflect the general characteristics of rule learning. Intralingual errors can be due to overgeneralization of rules, incomplete application of rules, ignorance of rule restrictions and false hypothesis. Third, developmental errors occur during the process of building hypothesis about the target language (Richards (1971), as cited in Heydari and Bagheri, 2012, p. 1584). However, the distinction between intralingual errors and developmental errors seems to be unclear (Schacheter and Celce-Murcia, 1977, as cited in Ellis, 1994, P. 58). For that reason, the classification has been revised. According to Heydari and Bagheri (2012, p. 1584), Richards (1974) classifies errors according to their sources into two categories : interlingual errors caused by mother tongue interference and intralingual and developmental errors caused during the process of second language learning or caused because the difficulty of the language itself.

However, it is sometimes difficult and unclear to identify the real sources of errors. As it is not easy to make differences between interlingual and intralingual errors, it is more difficult to distinguish between the different types within the intralingual errors. Accordingly, other experts proposed other categories of learners’ errors (Ellis, 1994, P. 59). However, according to Heydari and Bagheri, (2012, p. 1585), Richards’ division have been considered by most researchers to base and elaborate their own classifications of categories.

2. Methodology

To carry out this research, a particular research methodology was followed to analyze and interpret the test results.

1. Research questions: This research work is conducted for the purpose of finding out how data obtained from diagnostic grammar tests should be examined and used to improve instruction and support students’ grammar learning. An attempt of studying the difficulties encountered by pupils when using tenses in English was taken as a case study for this work through answering the following questions:

• What types of errors do high school learners make when using tenses in English ?

• What are the sources of such errors for those learners ?

• How can teachers shape instruction based on these data so that they can better the acquisition of such grammar point ?

1. Research Design This research is designed by using quantitative and qualitative research approaches. Quantitative methods deal with data in a numerical form. However, qualitative methods deal with data such as the use of experiences and opinions.

2. Participants: An important element in the process of conducting any research work is the sample population. The population of this study consisted of forty-one pupils (41) from Imam Malek High School, in Naama, Algeria.

3. Research Instruments: A diagnostic grammar test was used as a research instrument. The learners’ responses were being corrected, the errors that they committed were identified, categorized and explained for the purpose of finding out the most common errors and the reasons behind making them. It included six sentences in which the learners were asked to put the verbs between brackets in the correct forms. Learners were also given a questionnaire in which they ticked the boxes appropriate for them. Its main aim is to identify the sources of such errors according to the learners’ point of view; either interlingual errors or intralingual errors, or they gave their own factors in the box intended for that. In the table, there were types of errors, in front of them some examples and their correction and the sources; either interlingual or intralingual,

3. Findings and Discussion

3.1. Data Analysis

Interpreting the test results includes an analysis of the pupils’ marks and a study of the student’s responses for the purpose of answering the questions raised in this study. This study identifies the types and frequency of errors committed by the third year pupils to target areas of difficulties.

3.1.1. Evaluation of the Test Results

The test results were studied and analyzed for the purpose of providing useful information about the degree of those learners’ ability to use English tenses. The study of the test marks of forty-one (41) pupils provided clear information about their level in such grammar point. In the following table, the test results are displayed in increasing intervals from the lowest level to the highest one.

Table 4.1. Percentages of the Test Results

Mark (out of 20)	Number	Percentage
0 - 4.99	25	60.97 %
5 - 8.99	10	24.39 %
9 - 9.99	01	2.43 %
10 ≥	05	12.19 %

Source : Prepared by the author

Depending on the above table, the pupils’ level in using tenses was very weak since most of the marks were less than five (5) out of twenty (20), representing 60.97 % of the total number of the marks. Furthermore, the total number of the marks below the average represented thirty-six (36), representing a percentage of 87.80 %. However, just five (05) pupils got the average or more, representing a percentage of 12.19 %. This low level in English grammar competence was confirmed also when calculating the mean of this test that was (5.34).

3.1.2. The percentages of the correct answers

The total number of pupils was forty-one (41). They were asked to conjugate six verbs in the correct form. As we had 41 pupils, the total number of answers was 246. To provide an overall idea of the degree of difficulty of such task, we calculated the frequencies and percentages of the correct answers and the wrong answers as well as the avoided ones.

Table 4.2. Type and Frequency of Answers

Types of answers	Correct answers	Absence of answers	Wrong answers
Number	33	35	178
Per cent	13.41 %	14.22 %	72.35 %

Source : Zhang, 2016, p. 1580

What can be understood from the table above is that the learners had a difficulty in supplying the correct tense of verbs since the percentages of the wrong answers and the avoided ones form 86.57 % from the total number of answers. Depending on Crompton’s (2011) accuracy rate (after Dulay and Burt, 1974) of 90 % or higher as a sign of acquisition (as cited in Al-Mekhlafi, 2013, p. 60), 13.41 % is a surprisingly very weak rate.

3.1.3. Abbreviations and meanings of errors types

The analysis of the learners’ responses indicated various grammatical errors. These errors were identified and used in a form of abbreviations which are used as keys when reading the tables and the bar graph. The following table is an illustration of these keys.

Table 4.3. Abbreviations of Error Types in English tenses

Abbreviation	Full words	Explanation
WT WFV WV Inf ET-V	Wrong Tense Wrong Form of Verb Wrong Verb Infinitive Erroneous Tense and verb form	Pupils used wrong tense instead of the correct one. Tense was correct but the verb form was wrong. Another verb was used instead of the given one. Infinitive should be used after TO but other verb forms were used. Pupils used tenses and verb forms that did not exist.

Source : Mungungu, 2010, p. 53.

The types of errors which were identified, were illustrated through the following examples.

Table 4.4. Examples of Types of Errors Identified in English tenses

Examples of error identified	Definition of error type
Years ago, it is difficult for people to send their children to school (was)	WT
This table is maked of metal and wood. (is made)	WFV
Some pupils will go better results if their teachers take care of them. (will get)	WV
Years ago, it was difficult for people to sent their children to schools. (send)	Inf
I to meetn’t him for ten years.(haven’t met)	ET-V

Source : Mungungu, 2010, p. 54

Depending on the table above, five error types were recorded when pupils were asked to supply the correct forms of verbs. They used wrong tenses, wrong forms of verb, a completely other verb instead of the given ones, other verb forms instead of the infinitive and other tenses and verb forms that do not exist.

In the following step, the types of errors made to do such task are presented according to the number of their frequency and in a form of percentages

3.1.4. Frequency of Types of Errors

In the following table, the types of errors made in such task are presented according to the number of their occurrence and in a form of percentages :

Table 4.5. Frequency of Error Types

Examples of error identified	Definition of error type	Number	Per cent
Years ago, it is difficult for people to send ( was)	WT	71	40.11 %
This table is maked of metal and wood. (is made)	WFV	38	21.46 %
Some pupils will go better results if their teachers take care of them. (will get)	WV	12	6.77 %
Years ago, it was difficult for people to sent their children to schools. (send)	Inf	20	11.29 %
Ito meetn’t him for ten years. (haven’t seen)	ET-V	36	20.33 %

Source : Mungungu, 2010, pp. 57-58.

The overall number of errors was found to be 177 errors. What has been noticed from the previous table is that the learners did not know tenses since they used the wrong tenses instead of the correct ones. This is clearly noticed in its percentage that presents the highest one (40.11 %). The next most common error type was wrong verb form in a percentage of 21.46 %. Pupils knew the suitable tense but they did not know the correct form of verbs. In some cases, learners supplied erroneous tenses and verb forms that do not exist at all. This forms the third common error type in a percentage of 20.33 %. Some other errors were found such as conjugating the verbs after TO in a percentage of (11.29 %) or using another verb instead of the given one in percentages of (6.77 %).

3.1.5. Analysis of the Questionnaire Results

The following bar graph illustrates the learners’ main sources leading to make such errors according to them.

Bar graph 4.1. The learners’ main sources of errors

Source : Prepared by the author

The results showed that most of the learners’ grammatical errors in using English tenses were intralingual errors and small proportion of them were interlingual. The rest of them were due to other factors mentioned by some learners as carelessness and inattention.

3.2. Discussion

The results of the questionnaire showed that most of the learners’ grammatical errors in using English tenses were intralingual errors and small proportion of them were interlingual or due to other factors mentioned by some learners as carelessness and inattention.

According to the test results, our findings show that learners did not know tenses since they used the wrong tenses instead of the correct ones. Even if they knew the suitable tense, they did not know the correct form of verbs ; either they supplied erroneous tenses and verb forms that do not exist at all or using another verb instead of the given one.

The analysis of the questionnaire was followed by an analysis of the most frequent errors committed by those learners depending on Richards’ division and subdivision (1974). According to him intralingual errors are subdivided into three main types : overgeneralization (from one structure to another), ignorance of rule restrictions (within the structure itself) and incomplete application of the rule. However, it was difficult to prove that the studied error has a specific cause but we tried to consider the greatest probability. This is what has been confirmed by Mukattash (1981) who states that there is no way of proving that any given error type has a specific cause.

Some examples of misuse of tenses and wrong verb and auxiliary form were chosen for the analysis

• Years ago, it will be/ is difficult …. (was)

The error is in the use of the future simple or the present simple tense where the past simple is required. It is clear that learners generalized the rule of future tense formation or the present simple tense. It is due to incomprehensibility of tenses or ignorance of time indicators according to learners. This led them to misuse tenses as Richards (1974, p. 38) states that pupils sometimes apply a rule in areas where it is incorrect and inappropriate.

• This table is maked of ice and dust.(made)

In this sentence, the learners ignored the rule restriction of past tense formation and over-generalized the rule of adding (-ed) to the verbs that should take another form (irregular verbs).

1. I don’t met him for ten years.

2. I to meetn’t him for ten years. (haven’t seen)

The verb auxiliaries have also been omitted or misused. This shows that learners have more difficulties in using auxiliaries in forming verbs in complex tenses. The auxiliary verbs are often problematic for L2 learners since there are certain rules on how to use them (Taher, 2011, p. 26). In these sentences, these error types are classified as an incomplete application of the rule. This type of error is probably due to lack of knowledge about form of complex tenses, verb and auxiliaries forms. However, in sentence ‘b’ ‘not’ is added in its abbreviation form directly to the verb. It may be classified as an incomplete application of the rule or a direct translation from their dialect.

1. Years ago, it was difficult for people to sent … ( send)

2. Some pupils will go better results if their teachers take care of them. (will get)

The verb should be written in the infinitive form in sentence ‘a’. It is an intralingual error due to the ignorance of such rule. In sentence ‘b’, the verb is omitted and another verb occurs. This may occur as a result of inattention or carelessness, or inability to make difference between verbs.

Depending on what has been said above, it can be revealed that the use of verbs in the correct tenses and forms seems to be so difficult to those learners the errors that they made were both from interlingual and intralingual interference. However, their biggest number of errors is due to intralingual factors. More precisely, most of them were caused by overgeneralization or incomplete application of rules. They are items produced both by the learner which reflect not the structure of the mother tongue, but problems based on partial exposure to the target language (Richards (1970), as cited in AbiSamra, 2003).

Based on the analysis above, some practical remedial teaching strategies and teaching plans are suggested to deal with such difficulties for achieving effective learning.

4. Remedial Teaching and Educational Decisions Making

The main step in educational diagnosis is identifying the learners who have problems and need help. After the evaluation of the test marks, the teacher makes lists of learners who are below average, average or above average. It is necessary to make them in different groups if it is a mixed-ability class, depending on areas of difficulties and the pupils level of competence. In the current study, all learners are below average except five pupils out of forty-one. This means that almost all the pupils have troubles and need help.

The next main step is identifying the areas of difficulties through analyzing the errors that the learners commit and discovering the causal factors behind making them. Accordingly, teachers decide which learning items need to be taught in details and which need to be dealt with in brief. Drawing pupils’ attention to grammatical errors and identifying their sources can be effective in calling their attention to grammatical forms.

The ultimate aim of diagnostic education is to support pupils according to their abilities and needs. That’s why, the next main step is adapting school syllabuses and teaching strategies accordingly. Teaching objectives can be adapted in consideration to teaching priorities. Teachers can set some teaching objectives which help in making the acquisition of the new content easy to achieve as including grammatical structures that are not included in the syllabus, but needed as a basic step to teach certain structures. In the same vein Larsen-Freeman (2009) suggests adopting a ‘grammar checklist’ in which “teachers have an unordered set of grammar structures they need to teach in a way that attends to their pupils’ readiness to learn” (2009, p. 530). Moreover, the grammar points should be classified into different levels and taught through brief and simplified steps to facilitate comprehension and acquisition. Some examples are suggested such as teaching the forms of auxiliaries needed in the complex tenses before teaching those tenses, and teaching simple tenses before complex ones in well-illustrating examples and simplified and graded teaching activities. This is what is known as teaching some structures in gradual sequences. This can be beneficial to make learners avoid committing persistent errors.

Remedial teaching can be also fostered through involving the learners in rich structured input of the target structures related to those errors. Teachers should use new teaching materials that engage in learners motivation and challenge to overcome those difficulties and stimulate their potentials.

Another technique based on the diagnostic test results is to bring learners with similar learning difficulties together for additional help, time and practice. However, learners who don’t have much difficulties engage in enrichment practice more difficult than those given to their friends. This helps a lot in breaking up of boredom and lack of interest. Even, teachers can get help from pupils who perform better in that grammar point to be responsible for helping their classmates with learning difficulties.

Another essential point is individualized instruction. Teachers have the responsibility to support each pupil because learners don’t have the same abilities and needs and therefore they should adapt instruction based on their strengths, weaknesses and interests. Accordingly, they can implement individualized educational programmes in which they provide intensive remedial support, differentiated instruction, lesson plans, teaching activities, teaching strategies and other classroom techniques which distinguish from each other according to the needs of those learners.

In remedial teaching, teachers should regularly observe and evaluate the performance of pupils in class and through home works. It is of paramount importance to build a mutual trust between the teacher and the learners who need help and know how they think through listening to them carefully.

Conclusion

This research describes the case study which deals with how data obtained from diagnostic grammar tests should be examined, interpreted and used to improve instruction and support students’ grammar learning through analyzing the test results and the pupils’ questionnaire and focusing on the most frequent errors and the most common sources behind making them. The research findings revealed that the errors made by those pupils, from the most common to the least ones were found to be wrong tenses, wrong verb forms, erroneous tenses and verb forms, the absence of the infinitive form after ‘to’ and wrong verbs. Learners did not know tenses since they used the wrong tenses instead of the correct ones. Even if they knew the suitable tense, they did not know the correct form of verbs ; either they supplied erroneous tenses and verb forms that do not exist at all or using another verb instead of the given one. Even, they did not put the verb in the infinitive form after ‘to’. The causes behind making such errors were both due to interlingual and intralingual interference. Whereas, the errors caused by the learners’ mother tongue were in a very small proportion. However, intralingual errors are mainly due to overgeneralization and incomplete application of the rules.

Based on the data obtained from diagnostic assessments, teachers can make efficient educational decisions that improve the quality of grammar teaching as well as learning. They can adapt school curricula, teaching objectives and teaching materials. They can plan differentiated lessons, lesson plans, teaching strategies, and use other classroom techniques to help all learners in the classroom learn successfully. Besides, individualized instruction has proved its efficacy within classes of mixed abilities and needs. Teachers have the responsibility to support each pupil and therefore they should adapt instruction based on individual strengths, weaknesses and interests. In this manner, educational diagnosis can help a lot in enhancing the effectiveness of learning.