English Language Teaching and Linguistics Studies ISSN 2640-9836 (Print) ISSN 2640-9844 (Online) Vol. 4, No. 4, 2022 www.scholink.org/ojs/index.php/eltls 40 Original Paper Acquisition of Genitive Case by Bilingual Guilaki-Persian English Learners Maryam Tahvildary Biderooni 1 , Ali Akbar Jabbari 1* , & Yasaman Nasiriani 2 1 English department, Yazd university, Yazd, Iran 2 Islamic Azad university, Yazd branch, Yazd, Iran * Ali Akbar Jabbari, English department, Yazd university, Yazd, Iran Received: August 15, 2022 Accepted: September 28, 2022 Online Published: October 10, 2022 doi:10.22158/eltls.v4n4p40 URL: http://dx.doi.org/10.22158/eltls.v4n4p40 Abstract The present study focuses on recognition and production of the English genitive cases with similar structure in Guilaki (i.e., possessive determiners and possessive relations) or Persian (i.e., non-possessive relations) at initial state of EFL acquisition. In this regard, the researcher selected the most proficient Guilaki and Persian speakers-beginner EFL learners who were comparably aware of the structures under study to establish L3 and L2 groups. Both groups equally comprised 30 female third-grade junior high school English learners. The statistical analyses on GJT and Translation tests of the L3 group suggested different levels of cross-linguistic influence, and hence partially supporting FT/FA hypothesis, L2 transfer hypothesis or CEM for each form of genitive case. Moreover, the findings indicated a possible association between the L3 group’s poor performance and their incomplete L1 acquisition due to the intense contact with the majority language (i.e., Persian as L2). Consequently, EFL teaching through learners’ language background can improve their English and preserve their background languages. Keywords natural bilingual, genitive cases, majority language, Persian and Guilaki languages 1. Introduction The serious international attempts in the area of multilingualism that have been initiated since 1992 put multilingual education in the spotlight and drew special attention towards it in many multilingual communities. Although Iran is historically known as one of the ancient multicultural, multilingual countries, it is still treated as a monolingual community consisting of several dialects and accents. These publically assumed dialects not only differ from Persian as the majority language in terms of www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 41 Published by SCHOLINK INC. phonological, lexical, syntactic and semantic aspects but also remain distinctive as they are not mutually intelligible to Persian speakers. Therefore, from sociolinguistic point of view, they should be regarded as independent languages. To put it simply, the crucial factor that discriminates a language from a dialect is the extent of being mutually intelligible (Wardhaugh, 2006). More reassuringly, the increasing number of scientific works by linguists (e.g., Dabir-Moghaddam, 2001, 2006; De Caro, 2003; Larson, 2009; Paul, 2011; Vafaeian, 2012) on the syntactic structure of Iranian supposed dialects prove that they are independent languages (e.g., Kurdish, Lorish, Guilaki, Turkish, Tāleshi, etc.) and their speakers are in fact natural bilinguals within Iranian Persian-speaking, monolingual community. 1.1 Multilingualism within Heritage Language Communities In the area of multilingualism, the most up-to-date linguistic issue is the preservation of heritage languages (HLs) that are significantly under the effect of bi- and multilingualism. According to Rothman (as cited in Aalberse & Muysken, 2013), HL is a home language which is crucially under the influence of the societal majority language. Moreover, it is acquired through natural exposure but with qualitatively and quantitatively different input. While emphasizing Rothman’s criteria for HL, Aalberse and Muysken (2013) have added some conclusive defining parameters related to cultural aspect of HL, and hence defining it as a community language with cultural value and long history spoken by the people of common ancestry. In spite of the growing global concern, the issue of HL preservation is still something new to Iranian language scholars. In other words, the fact that Iranian old languages are actually HLs possessing their own specific linguistic context have always been overlooked. Anyhow, it cannot be ignored that many Iranian researchers (e.g., Dibaj, 2008; Esmae’li & Kassaian, 2011; Salimi, 2012; Shooshtari, 2009) have already devoted their studies to these languages, but never considered them HL deserving special focus in their own right. The present study centered on Guilaki as an Iranian HL that, according to many researchers (e.g., Paul, 2011; Vafaeian, 2012), possesses all the characteristics of a language and is mutually unintelligible to the speakers of other Iranian languages. The objective was to draw attention to EFL learning situation of natural bilingual Guilaki-Persian EFL learners in their own HL context, that is, Guilān province located in the north of Iran. More specifically, the focus was on the effect of Guilaki English learners’ language background (i.e., Guilaki as L1and Persian as L2) on the acquisition of English genitive cases, namely possessive determiners as well as possessive and non-possessive relations in the instructional setting. 1.2 Genitive Cases in Guilaki, Persian, and English Due to the fact that the rules concerning the position of modifiers are not universal, the researcher compared the structure of genitive cases across the three languages, namely Guilaki, Persian, and English. The idea was to highlight the existing similarities and differences, and then to examine the www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 42 Published by SCHOLINK INC. probable challenging situations that might arise for Guilaki EFL learners at initial state of learning these structures. To that end, the structures under study were organized into two contexts as follows: The first context includes two structures, namely possessive determiners and possessive relations. Contrary to Persian, possessive determiners always precede nouns in both Guilaki and English (see Example 1). Possessive determiners His shirt Unə pirhán (Guilaki) Pirāhán-e + ū (Persian) Shirt-EZ + possessive determiner In Guilaki and English possessive relations (i.e., as the second structure), the modifier precedes the modified noun, while in Persian, it follows the modified noun (see Example 2). Moreover, the linguistic nature of the particle that links the modifier to the head noun is different in Persian and Guilaki. In Persian, this particle is called “Ezafe” (EZ), and it is added to the head noun. However, according to Larson (2009), the position of EZ is reversed in Guilaki in a way that it cliticizes to the modifier. Therefore, it is called “Reverse Ezafe” (REZ). Possessive relations The boy’s book Kuták-ə kitáb (Guilaki) Boy-REZ + book ketāb-e + pesár (Persian) book-EZ + boy In brief, the structural similarity of Guilaki and English possessive determiners and possessive relations could hypothetically be a privilege for Guilaki English (i.e., as L3) learners, while Persian differing structures a handicap for Persian English (i.e., as L2) learners. The second context deals with other types of genitive cases generally classified as non-possessive relations in this study. Structurally both Persian and English forms of these phrases, in contrast with Guilaki, share the same structure where the modifier follows the modified noun (see Example 3). Non-possessive relations The door of the house Xonə dar (Guilaki) Dar-e + xāne (Persian) Door-EZ + house The existing structural similarity between Persian and English in terms of non-possessive relations can help both Guilaki and Persian English learners make a close connection between the elements of such noun phrases in Persian and English. Nevertheless, Guilaki English learners cannot find such relationships if they rely on their L1 differing structure. www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 43 Published by SCHOLINK INC. 1.3 Theoretical Framework Concerning the extent of cross-linguistic influences, the aim was to demonstrate the dominant reliance of L3 learners on either or both of their background languages. The following theories are considered to account for these effects: FT/FA hypothesis was first introduced into SLA research area by Schwartz and Sprouse (as cited in Bardel & Falk, 2007). They argued in favor of a full transfer model according to which all syntactic properties of the L1 initially constitute a base for the new developing grammar, which is constructed with the involvement of Universal Grammar (UG). In other words, they believed that a full acquisition of new grammatical properties takes place at the advanced levels (as cited in White, 2003). Thereafter, the advocators of UG (e.g., Leung, 2003; Shooshtari, 2009) used this hypothesis to offer more explanation about the role of transfer in multilingualism. The idea of Cumulative Enhancement Model (CEM) was first brought up by Flynn, Foley, and Vinnitskaya (as cited in Flynn, 2008) and later on verified by other researchers (e.g., Salimi, 2012). They believed that all previously learned languages (L1, L2, …Ln) may act as a source for transfer, but the L2 only supersedes the first language when the structure searched for is not present in the L1. Furthermore, Flynn (2008) noted that the prior language(s) could be neutral or enhancing in the subsequent language acquisition. L2 transfer hypothesis has been originated from the “L2 status factor” first proposed by Hammarberg and Williams (as cited in Bardel & Falk, 2007). According to this idea, among the languages known to the learner (i.e., L1 and L2[s]) the L2 is more likely to have an impact on the process of L3 acquisition. To prove the efficiency of Hammarberg’s idea, Bardel and Falk (2007) carried out a study to investigate this issue. They concluded that in L3 acquisition, the L2 acts like a filter making the L1 inaccessible, that is, transfer from L2 to L3 but not from L1 to L3. Accordingly, they developed the L2 status factor into the “L2 transfer hypothesis”. In the light of the above-mentioned theoretical ideas, the present investigation tried to address the following research questions: RQ1: Do Guilaki English learners face any difficulties acquiring English noun modifiers corresponding to those of Guilaki but differing from those of Persian? RQ2: Do Guilaki English learners, like Persian English learners, face any difficulties acquiring English noun modifiers corresponding to those of Persian but differing from those of Guilaki? 2. Method 2.1 Participants Since the purpose of the present study called for working with students who were still acquiring English genitive cases, third-grade junior high school students were considered as the most appropriate www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 44 Published by SCHOLINK INC. participants. Such students had already been introduced to English genitive cases but were still in the process of complete recognition of these structures and development of their full-fledged production ability. Initially, 60 female third-grade junior high school students in the age range of 13 to 15 from Tehran along with 66 ones from Guilān were chosen to take part in the preliminary selection procedures. They were actually Persian (i.e., as L1) and Guilaki (i.e., as L1) speakers who were learning English as their second or third language, mostly, for about two to eight years as extracurricular activity. Obviously, no effective role was assumed for gender in this study. The following instruments were implemented to from the main groups from this community. 2.2 Instrumentation As far as this study was concerned, checking English grammatical knowledge took precedence over the other language skills. Due to the out-of-school experience of Persian and Guilaki students in EFL learning, the second version of paper and pencil OQPT designed in 2001 was conducted to choose the beginner-level EFL learners. In addition, two almost similar questionnaires, namely L3Q and L2Q, were designed and written in Persian respectively for Guilaki and Persian speaking participants. In preparing the L3Q for the Guilaki speakers, 13 questions generally concerning the demographic and language background information were developed. The questions asked, for example, about the outset, period, and extent of use of Persian as the national language as well as Guilaki as their HL in different contexts of their everyday life. To draw the same information and choose the most proficient Persian speakers, the researcher included 11 questions in the L2Q designed for the Persian speakers covering almost the same items. The objective was to select the respondents who used Persian as the only medium of daily communication as well as the sole linguistic reliance at initial state of acquisition of English genitive cases. Furthermore, the participants’ specific knowledge and acquisition status of English genitive cases were ascertained through General English test designed on the basis of the grammatical content of the second- and third-grade junior high school English textbooks (see Example 4). This is my………………. . (’s, father, clock, of) To choose the suitable members of the main groups, the researcher first administered OQPT to the selected community. Consequently, they filled in the questionnaires and took General English test. After examining the demographic information, as well as the performance on OQPT and General English test, the main groups, namely the L2 (i.e., the Persian group) and the L3 (i.e., the Guilaki group) groups, were established. The L2 group was composed of 30 participants whose L1 was actually Persian and almost unaffected by any other Iranian languages. The L3 group, on the other hand, included the same number of Guilaki students who were all Guilaki by birth and proficient in Guilaki and Persian. According to the EFL cross-reference chart of OQPT for the first part of the test, the results of the L2 (i.e., ranging from 3 to www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 45 Published by SCHOLINK INC. 11, M = 6.33) and L3 (i.e., ranging from 2 to 10, M = 5.84) groups verified their English language level as beginners. Moreover, the analysis of General English test results indicated no significant difference in scores for the L3 (M = 14.67, SD = 3.02, maximum score = 20) and L2 groups, M = 13.57, SD = 4.31, maximum score = 20; t (52) = 1.15, p = .26 (two-tailed) proving the comparability of both groups in terms of the knowledge of genitive cases. After establishing the main groups, the researcher administered the three main tests including one GJT, and two Translation tests. GJT aimed to check the participants’ recognition ability in terms of the English genitive cases. To that end, the students of both groups were asked to determine the un/grammaticality of the items containing the structures under study as well as some distractors. To point the students in the right direction, the researcher prepared an answer sheet containing three-options (see Example 5) to control for the possibility of rejecting the sentences on the basis of the English prescriptive rules mentioned in the students’ textbooks. The I don’t know option encouraged the students to avoid any guess by chance selection. Incorrect English possessive relation item The hair’s boy is not black. Correct Incorrect I don’t know The boy’s hair is not black. (√) Choosing “correct” option (i.e., wrong answer) = Persian effect In order to explore the possible cross-linguistic influence of Persian and Guilaki on the participants’ recognition of English genitive cases, some assumptions were taken into consideration (see Table 1). Table 1. The Assumptions behind GJT Items Context Grammatical items Ungrammatical items 1 Possessive determiners Possessive relations English and Guilaki structures Persian structures 2 Non-possessive relations English and Persian structures Guilaki structures Translation tests were designed in Persian (i.e., Per-Eng Translation test) and Guilaki (i.e., Guil-Eng Translation test) versions to examine the production ability of main groups (see Examples 6 & 7). The L3 group did both versions, while their L2 counterpart only translated the Persian items into English. The evaluation of the produced answers was based on their extent of proximity to the correct English structures that might be similar to Guilaki or Persian. The use of different Guilaki or Persian structures was also marked as a sign of negative effect. (Guil-Eng Translation test, item no. 2): Possessive determiners In mi jaγlə isə. (Transcription of Guilaki sentence) This my child is (Gloss) www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 46 Published by SCHOLINK INC. This is my child. (English equivalent) (Per-Eng Translation test, item no. 2): Possessive determiners In xāne-ye man ast (Transcription of Persian sentence) This house-EZ my is (Gloss) This is my house. (English equivalent) 2.3 Procedure The first test after establishing the main groups was GJT. Both groups judged the un/grammaticality of the items including genitive cases and some distractors in 10 minutes. Since the L3 group was required to do both Translation tests, they had to be administered in a way that the test effect was minimized. Therefore, they did Guil-Eng Translation test three days after GJT. The test takers were advised against translating Guilaki items first into Persian and then into English. In case they did not know the Persian equivalent of Guilaki words, they were requested to leave them unanswered. As their first experience in translating from Guilaki into English, it took the L3 group 20 minutes to finish Guil-Eng Translation test. Per-Eng Translation test was taken by the L3 group seven days after the Guilaki version and by the L2 group four days after GJT. Both groups finished it in 17 minutes. Eventually, to perform the statistical analysis on participants’ results, the researcher devised the following codification for their answers (see Table 2 & 3). Table 2. Codification of Guilaki Group’s Answers to the Tests Context Structures Codes Translation tests GJT Context one: L1(Guil) = L3 (Eng) L1(Guil) # L2 (Per) Possessive determiners Possessive relation Correct: Guil/Eng structure Incorrect: Per(L2) structure Irrelevant/Empty Correct: Guil/Eng structure Incorrect: Per(L2) structure No idea/Empty Context two: L1 (Guil) # L3(Eng) L2 (Per) = L3 (Eng) Non-possessive relation Correct: Per(L2) /Eng structure Incorrect: Guilaki structure Irrelevant/Empty Correct: Per(L2) /Eng structure Incorrect: Guilaki structure No idea/Empty Note. Guil = Guilaki (L1), Per = Persian (L2), Eng = English (L3). www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 47 Published by SCHOLINK INC. Table 3. Codification of Persian Group’s Answers to the Tests Context Structures Codes Translation tests GJT Context one: L1(Per)#L2(Eng) Possessive determiners Possessive relation Correct: Eng structure Incorrect: Per(L1) structure Irrelevant/Empty Correct: Eng structure Incorrect: Per (L1) structure No idea/Empty Context two: L1(Per)=L2(Eng) Non-possessive relation Correct: Per (L1) /Eng structure --- Irrelevant/Empty/ Wrong Correct: Per(L1) /Eng structure --- No idea/Empty/ Wrong Note. Per = Persian (L1), Eng = English (L2). It should be noted that since any incorrectly recognized or produced “of structure” cannot be influenced by the L2 group’s background language, they were also classified as “Wrong” under code 3. All distractors were ignored in the codification process. The dictation errors in Translation tests were also not attended to. 3. Results The codified answers of each participant to the items of each test were fed into the version 16 of the SPSS software separately and the following analyses were conducted on them. According to the outcome of descriptive statistics, both groups were similar in terms of the recognition of possessive determiners and possessive relations. However, the L2 group’s non-possessive relations results (M = 0.63, SD = 0.23) were better than those of the L3 group (M = 0.49, SD = 0.31). In Per-Eng Translation test, both groups performed similarly in terms of possessive determiners; nonetheless, the L2 group’s rate of correct possessive relations (M = 0.65, SD = 0.41) was clearly higher than that of the L3 group (M = 0.48, SD = 0.45). The same situation was also observed in the results of correctly produced non-possessive relations (the L3 group: M = 0.40, SD = 0.42; the L2 group: M = 0.52, SD = 0.40). Comparing the L3 group’s performance on both Translation tests indicated the comparability of their results in possessive determiners and non-possessive relations. On the other hand, while the negative influence of their L2 on the production of possessive relations remained analogous across the two Translation tests; their correct production did not improve in Guil-Eng Translation test (31%) , compared to the Persian version (48%). www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 48 Published by SCHOLINK INC. It should be noted that the L3 group’s mean scores of correctly and incorrectly recognized or produced structures are representative of their L1 or L2 transfer. Hence, the extent of difference between these scores signifies the degree of their reliance on either or both of their background languages. In this regard, the paired-samples t-test conducted on the L3 group’s results revealed a significant difference between the effect of Guilaki and Persian languages on the scores of: possessive determiners in GJT(t [29] = 10.7, p < .001 [two-tailed], mean difference = 0.59, 95% CI [0.48, 0.71], eta squared = .66), Per-Eng Translation test ( t [29] = 11.24, p < .001 [two-tailed], mean difference = 0.65, 95% CI [0.53, 0.76], eta squared = .69), and Guil-Eng Translation test ( t [29] = 14.9, p < .001 [two-tailed], mean difference = 0.7, 95% CI [0.6, 0.8], eta squared = .79). possessive relations in Per-Eng Translation test (t [29] = 3.7, p = .001 [two-tailed], mean difference = 0.38, 95% CI [0.17, 0.58], eta squared = .19) and the Guilaki version (t [29] = 2.6, p = .015 [two-tailed], mean difference = 0.23, 95% CI [0.05, 0.42], eta squared = .10). non-possessive relations in Per-Eng Translation test (t [29] = 3.6, p = .001 [two-tailed], mean difference = 0.32, 95% CI [0.14, 0.5], eta squared = .18) and the Guilaki version (t [29] = 4.23, p < .001 [two-tailed], mean difference = 0.29, 95% CI [0.15, 0.43], eta squared = .24). According to Cohen’s (as cited in Pallant, 2007) guidelines, the effect size was large indicating the L3 group’s more use of one background language than both of them in the recognition and production of this structure Nevertheless, the difference between the effect of two languages on the recognition of possessive relations: t (29) = 1.7, p = .1 (two-tailed), mean difference = 0.17, 95% CI [- 0.04, 0.37]; and non-possessive relations: t (29) = 0.85, p = .4 (two-tailed), mean difference = 0.08, 95% CI [-0.17, 0.28] was not significant. It suggested that the L3 group used both of their L1 and L2 almost equally in the recognition of possessive and non-possessive relations. Moreover, the multivariate tests indicated a substantial main effect for context in terms of correct recognition of the structures under study, Wilks' Lambda = 0.58, F (2, 57) = 20.94, p < .001, partial eta squared= .42. The effect size suggested a considerable change in the mean scores of correctly recognized structures across the two contexts for both groups, mean difference = 0.123, p = .001, 95% CI [-0.203, -0.043]. Concerning the negative transfer in GJT, a statistically significant main effect for group was also detected, F (1, 58) = 28.5, p < .001, partial eta squared = .33. Considering Cohen’s (as cited in Pallant, 2007) guidelines, the effect size was substantially large. In relation to correct production, the multivariate tests indicated a statistically significant main effect for Translation across the two Translation tests for the L3 group (F [1, 58] = 4.34, p = .04, partial eta squared = .07). Moreover, a substantial main effect for context with large effect size based on Cohen’s (as cited in Pallant, 2007) guidelines was observed in: Per-Eng Translation for both groups, Wilks' Lambda = 0.62, F (2, 57) = 17.67, p < .001, partial eta squared = .38, mean difference = -0.163, p = .001, 95% CI [-0.262, -0.063]; and www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 49 Published by SCHOLINK INC. both Translation tests for the L3 group, Wilks' Lambda = 0.57, F (2, 57) = 21.9, p < .001, partial eta squared = .44, mean difference = -0.154, p = 0.001, 95% CI [-0.255, -0.053]. All the aforementioned statistical results are discussed in the following section. 4. Discussion & Conclusion As to the purpose of the present study, three main tests were developed, administered, and analyzed to ascertain the effect of Guilaki and Persian on the recognition (i.e., GJT) and production (i.e., Translation tests) of English genitive cases by the Guilaki English learners as the L3 group in comparison with their Persian counterpart as the L2 group. The idea behind the Per-Eng Translation test was that Persian items act as visual stimuli and hence, naturally exposing the groups more to the positive or negative effect of the related Persian structures. Additionally, this would help to explore the indirect positive or negative influence of Guilaki language on the L3 group. In addition, Guil-Eng Translation test was specifically designed for the L3 group to provide a situation in which they were provoked to use their L1 more than their L2. With these points in mind, the answers to the proposed research questions are as follows: The first research question addressed the two structures of the first context. Generally, considering the similar proximity and success of the L3 group in terms of the recognition and production of possessive determiners, one can conclude that they were effectively acquiring this structure through the dominant dependence on their L1. However, this advantage neither completely reduced or blocked the negative effect of the Persian differing structure nor helped them to outperform the L2 group. Specifically, the only benefit of using visual stimuli in Guil-Eng Translation test was the removal of the slight negative transfer (3%) observed in the Persian version. On the other hand, the comparison between the L3 group’s recognition and production of possessive relations suggested that this structure was not effectively acquired. As a result of this poor acquisition status, the L3 group’s attempts resulted in either more negative language effect in GJT or more production failure in Translation tests. In comparison, the L2 group was dealing properly with the acquisition of possessive relations. The answer to the second research question was dependent on the results of non-possessive relations. The contradictory results of the L3 group, especially the considerable fluctuation of recognition and production failure (GJT: 10%, Per-Eng: 52%, Guil-Eng: 56 %) across the three tests were a clear indication of their difficulty in the acquisition of non-possessive relations. This handicap was easily covered at the recognition level in the guise of negative transfer from Guilaki language because their range of answers was limited to the three options. The L2 group, on the other hand, did not suffer from any negative transfer in the recognition and production of non-possessive relations because they had no related troublesome structure in the stock of their background language (i.e., Persian). Despite having this privilege, they produced unsatisfactory www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 50 Published by SCHOLINK INC. results, that is, high rate of recognition (36%) and production (48%) failure, indicating their acquisition difficulty in the second context. In summary, the L2 group outperformed their L3 counterpart in the two contexts of GJT and Per-English Translation test. These findings were in accordance with the conclusion of Shooshtari (2009), that is, bilingualism offers no privilege in L3 acquisition. In another similar study, Salimi (2012) observed that the L3 group, contrary to the present study, benefitted from their two background languages and achieved better results compared to their L2 counterpart. From another point of view, the L3 group’s poor performance can be put down to several factors such as their incomplete L1 acquisition and L1 illiteracy. Martinez-Gibson (2010) attributed the incomplete L1 grammar acquisition of HL speakers to the reduced language input during childhood. In addition, Cuza and Frank (2011) added the intense contact with the majority language as another factor affecting the incomplete HL grammar acquisition. More specifically, the Guilaki English learners were natural bilinguals who were easily and abundantly exposed to both Guilaki and Persian in their everyday life. The amount of exposure to each of their background languages not only could affect their L1 and L2 proficiency but also their reliance on them as the frame of reference for L3 learning. As the framework of this study, the three cross-linguistic hypotheses explained the L3 group’s performance as follows: The dominant reliance of the L3 group on Guilaki as L1 that was observed in the recognition and production of possessive determiners as well as the production of possessive relations was in accordance with the idea behind FT/FA hypothesis proposed by Schwartz and Sprouse (as cited in Bardel & Falk, 2007). That is, Guilaki as L1 played the initial active role in the development of these English structures. The principal dependence of the L3 group on Persian as L2 that was detected in the production of non-possessive relations can be cautiously explained through the L2 transfer hypothesis developed by Bardel and Falk (2007). In fact, the results only advocate the role of L2 as the dominant source of transfer but not its role as the filter blocking L1 access in the acquisition of L3 structures. The comparable dependence of the L3 group on both of their L1 and L2 that was noted in the recognition of possessive and non-possessive relations in GJT can be attributed to CEM proposed by Flynn et al., (as cited in Flynn, 2008). In effect, not only did both Guilaki and Persian assume a role in EFL learning but also Persian almost superseded Guilaki when it lacked the target structure. In the end, the inescapable conclusion is that the performance of the L3 group cannot be exactly attributed to the aforementioned ideas that are based on the results obtained from the studies performed in different linguistic contexts. Accordingly, all the approvals or rejections were expressed from a cautious perspective and should be regarded in that way. 4.1 Theoretical Implications Generally, the findings of this study produced the subsequent theoretical implications: www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 51 Published by SCHOLINK INC. The idea of L2 transfer hypothesis about the role of L2 as a filter that blocks any access to L1 in the acquisition of L3 structures is not always true; however, its complete rejection is beyond the jurisdiction of the present research. Flynn’s (2008) idea about the possible neutral role of the prior language(s) in the subsequent language acquisition should be interpreted as having no effective role than having no role at all. The effective idea behind almost any cross-linguistic hypothesis considered in the study on multilingualism might be challenged or nullified when: targeting the HL bi- or multilingual participants with parallel exposure to their background languages, studying the background languages with bi- or unilateral influence on each other, stimulating the participants with visual stimulus structurally similar to or different from the target structure, and when facing the situation in which the acquisition problem is more intense than cross-linguistic influences. 4.2 Pedagogical Implications From pedagogical point of view, the outcome of the present study produced three major implications. The primary shallow implication was that knowing Guilaki had no influential role in learning English genitive cases corresponding to the related structures of this language. However, if the students have the related Guilaki knowledge, raising their awareness of the structural similarity between Guilaki and English through the use of visual stimulus can diminish the negative effect of Persian differing structure or facilitate the translation of items (e.g., possessive determiners). Otherwise, the awareness raising may lead to more confusion and poor production (e.g., possessive & non-possessive relations). Accordingly, the second implication was that the explicit use of the knowledge of background languages as language teaching instruments can easily improve EFL learners’ language abilities. Nonetheless, it demands English language instructors’ familiarity with the structures of these languages. In this regard, Meher (2013) highlighted the need for specially designed materials to develop proper teacher-training modules with a special focus on teacher attitudes as well as bi- and multilingualism. According to her, an appropriate use of L1 in such programs may lead to a richer atmosphere for learning L2 and better learning outcomes for the students. In other words, the future language instructors should be multiple language speakers or aware of the knowledge of multiple languages. Maybe it is the time to pay serious attention to the language diversity in Iran as it was done in Spain some decades ago. Spain’s General Law of Education established in 1970 included regional languages and literature in the educational system of the corresponding communities from basic education onwards (Genís, 2012). Finally, the third and the most important implication of the present study was that teaching a foreign language through native languages helps to improve one and preserve the others. Nevertheless, it can only be accomplished through financial assistance of government, legal service of policy makers, full cooperation of educational officials, thoughtful plan of educational experts, and persistent efforts of motivated language instructors. www.scholink.org/ojs/index.php/eltls English Language Teaching and Linguistics Studies Vol. 4, No. 4, 2022 52 Published by SCHOLINK INC. 4.3 Suggestions for Further Research Similar studies on the other HLs could be carried out with any possible changes in the conditions of this research such as: using L1 and/or L2 oral stimulus before GJT, checking HL participants’ L1 and L2 proficiency through translation tests, having the participants undergo a related treatment before the tests, and so forth. As concluding remarks, with regard to future studies on Guilaki language in particular, the researcher suggests: scrutinizing the current role of language instructors of Guilān in the success or failure of Guilaki English learners, or working on other aspects of Guilaki language (e.g., phonology, vocabulary, etc.). Declarations Acknowledgement Not applicable Funding No funding was received for the current study. Competing interests The author declares no conflict of interest. Ethics approval and consent to participate The present study adhered to ethical considerations in educational research by obtaining informed consent from the participants and also by ensuring them regarding the confidentiality of the collected data. Availability of data The data will be available upon e-mail request to the corresponding author. 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