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Abstract

Trans Abstract

Narrative

Narrative is a type of discourse that refers to causally and/or temporally related events (Hughes, McGillivray, & Schmidek, 1997; Peterson, 1990). Constructing cohesive narratives requires integrating linguistic and pragmatic knowledge with cognitive skills (Boudreau, 2007). Since the narrative is based on mental schema (Stein & Glenn, 1979), a high level of complexity in discourse is required, and we can observe this complexity increasing with age (Crais & Lorch, 1994). At the age of two, children begin to talk about past events and they can talk about one or more events using story structure elements by the age of three to four (Kim, 2014). Children around age four begin to reflect on their experiences, feelings, and thoughts in their narratives (Stein, 1988). It is reported that at the age of five to seven, children begin to tell structured stories, including introductions, background, and outcomes (Morrow, 1985). At this age, they can include ‘where’, ‘when’, and ‘who’ information as they start to comprehend the concept of time, and therefore, they can logically make the story according to the event’s purpose (Kim, 2014).

Narrative skills play an essential role in children’s communication with various people around them. Through narrative, children engage in conversations with their parents (Nation, Clarke, Marshall, & Durand, 2004) and peers (Petersen, Gillam, & Gillam, 2008). Additionally, children acquire the traditions and values of the society to which they belong (Minami, 2002). In addition, narratives are essential in language, cultural, and academic fields (Petersen et al., 2008). Furthermore, their ability to use narratives predicts academic success and literacy outcomes (Bishop & Edmundson, 1987; Fazio, Naremore, & Connell, 1996; Fey, Catts, Proctor-Williams, Tomblin, & Zhang, 2004; O’Neill, Pearce, & Pick, 2004).

Narrative is the result of contextual interaction within sociocultural norms that form the premise and expectation of the speaker and the listener (Owens, 2016). When looking at the narrative performance of multicultural-multilingual children with different cultures and languages, it was confirmed that there may be cultural differences in the narrative structure (Champion, 1998; Gillam, Gillam, & Reece, 2012; Gorman, Fiestas, Pena, & Reynolds Clark, 2011; Mills, Watkins, & Washington, 2013; Tappe & Hara, 2013; Westby, 1994). However, the basic framework of the narrative structure is similar across various languages (Mandler, Scribner, Cole, & DeForest, 1980). A study examining the development patterns of children’s personal and fictional narratives in Korea and the United States also confirmed that the ability to produce narratives varies from person to person. However, most were similar to previous studies (Lee & Lee, 2005).

Children’s narratives are analyzed in terms of macro- and micro- structures (Justice et al., 2006). A representative method of analyzing macro-structure is ‘Story Grammar (SG)’, which helps to analyze the overall hierarchical structure of the story (Bamberg, 1987), and to understand the degree of organization of the story. On the other hand, micro-structures examine the ability to produce complex characteristics of language and it is analyzed based on vocabulary diversity (the number of words), linguistic complexity (sentence length), morpheme analysis, syntax, and cohesion. Previous research found narrative patterns in two groups of bilingual children: those with normal and delayed language development. Although there were differences between them in the results, it was also confirmed that there were differences in vocabulary diversity, such as the number of different words (NDW), and grammatical complexity, such as the mean length of utterance in words (MLUw) (Kapantzoglou, Fergadiotis, & Restrepo, 2017; Simon-Cereijido & Gutiérrez-Clellen, 2009).

Narrative Intervention

Narrative intervention is a language intervention method in which the interventionist deliberately includes targeted linguistic elements and features in a narrative, prompting the child to tell or retell the story (Spencer & Petersen, 2020). Narrative intervention is conducted using an approach that acquires and develops narrative structure based on the SG framework of Stein and Glenn (1979). This is supported by a body of research confirming the effectiveness of narrative language intervention across various populations, including individuals with language impairment (Hayward & Schneider, 2000; Hessling & Schuele, 2020), children with autism spectrum disorder (Gillam, Hartzheim, Studenka, Simonsmeier, & Gillam, 2015), preschool and school-age children (Gillam, Olszewski, Fargo, & Gillam, 2014; Spencer, Weddle, Petersen, & Adams, 2017), and bilingual children (Spencer, Petersen, Restrepo, Thompson, & Gutierrez Arvizu, 2019). Furthermore, it has been revealed that a bilingual intervention approach fosters beneficial effects, including a positive attitude towards both languages and the use of L1 to facilitate L2 learning (Thordardottir, Weismer, & Smith, 1997).

Several studies have revealed that narrative intervention for bilingual children is more effective when conducted in their first language (L1) rather than their second language (L2). The previous research conducted on Spanish (L1)-English (L2) children with typical development (Schoenbrodt, Kerins, & Gesell, 2003) divided the participants into two groups: the experimental group received intervention in their L1, while the control group received the intervention in their L2, examining the efficacy of the intervention. All participants underwent the intervention, which was administered once a week over eight weeks. To compare pre- and post-intervention improvements, narrative samples were obtained and analyzed for communication unit (CU) clauses, number of words, SG, and narrative style using both retelling and generation tasks. The results indicated that the experimental group showed a statistically significant improvement in communicative competence. Additionally, the experimental group demonstrated more significant success in the narrative style than the control group.

Another study identified the effectiveness of narrative intervention in improving vocabulary skills among 16 English (L1)-Hebrew (L2) preschool bilingual children, both typically developing (TD) and those with language impairment. The narrative intervention was conducted using Puente de Cuentos (Spencer, Petersen, & Restrepo, 2017), a translated version of Story Champs, the method utilized in this study. The intervention was administered twice a week, with six sessions in L1 and six sessions in L2, following a block design. The results indicated improvements in vocabulary in both languages. However, following the intervention in L1, enhancement was observed not only in L1 but also in L2 vocabulary. Thus, the study identified a language interaction effect wherein L1 intervention positively influenced L2 intervention outcomes. However, the opposite result-enhancement in L1 after L2 intervention-was observed only in children with high proficiency in their L1. It was further suggested that when children conceptualize using their L1 and translate into L2, the semantic connections are more rapid and robust compared to the opposite scenario.

Petersen, Thompsen, Guiberson, and Spencer (2016) discovered a cross-language interaction effect among bilingual Spanish (L1) and English (L2) children when employing narrative intervention in their L2. The study utilized Story Champs (Spencer & Petersen, 2016) which employs the same methodology as the current experiment. Participants were divided into experimental and control groups. In the results, bilingual children with typical development in the experimental group exhibited significant improvements in causal subordination and SG. Thus, the study demonstrated the interactive efficacy of intervention effectiveness from L2 to L1. On the other hand, children with language impairments in the experimental group did not exhibit a significant cross-language interaction effect. However, these children scored higher than those with language impairments in the control group. This suggests that children with language impairments in the experimental group might experience cross-language interaction with increased exposure and repetition.

As the multicultural-multilingual population has increased, about half of the world’s children are bilingual or multilingual at home or in their community (Place & Hoff, 2011). Statistics Korea’s multicultural population statistics show that the proportion of babies born into multicultural families accounted for 4.3% of all newborns in 2009. However, it increased to 5.9% in 2019 (Statistics Korea, 2020), and multicultural infants and toddlers surged from about 58,000 in 2008 to about 108,000 in 2009 (Park, Park, & Cho, 2020). Therefore, it is necessary to pay attention to providing appropriate services to multicultural-multilingual children.

As the multicultural population increases both domestically and abroad, many researchers have paid attention to providing appropriate services to multicultural and Korean-English bilingual children in the field of Speech-Language Pathology (Cho & Yim, 2020; Kang & Yim, 2022; Kim, Park, & Kim, 2019; Lee, 2020). Accurately identifying language development delays in bilingual children and providing the appropriate service is crucial, given the unique linguistic characteristics of bilinguals. Various studies have focused on accurate evaluation for Korean-English bilingual children (Han & Yim, 2018; Hong & Yim, 2014; Hong & Yim, 2019; Jo & Yim, 2017; Yim, Yoon, & Lee, 2016). However, the intervention of bilingual children is relatively recent in Korea (Cho & Yim, 2024), and speech therapists provide services based on their own experiences rather than clinical decisions based on evidence (Yang & Hwang, 2022).

Therefore, this study explored whether narrative intervention by L1 (Korean) improves children’s first language skills and facilitates their transfer to L2 (English). Children’s performance in the narrative is analyzed by the macro- and micro-structure of both L1 and L2. The research questions are as follows:

1. Is there a statistically significant difference in macro-/microstructure in Korean between TD children and children with language delay (LD) according to pre-/post intervention?

2. Is there a different degree of cross-language transfer in English between TD children and children with LD who receive Korean narrative intervention?

3. Are there significant correlations between children’s Korean and English vocabulary skills and their Korean and English narrative performance?

METHODS

Participants

Nineteen Korean-English bilingual children between the ages of 5 and 6 years participated in this study. Bilingual children with LD were 9 (M=5, F=4) and TD bilingual children were 10 (M=5, F=5). The age did not differ significantly across groups (LD: M=70.44, SD=8.18; TD: M=72.80, SD=8.30). All participants currently lived in Canada or the U.S.A. and attended preschool, where English was spoken as a primary language. For the primary caregivers of the study subjects, data on the overall development of the children were gathered by having them complete the Korean Brief Parent Report (KBPR; Han & Yim, 2018), a parent report-type child language ability evaluation tool, along with Parental Language Environment Questionnaire (PLEQ; Yim et al., 2020) in an online format. The criteria for selecting bilingual children based on the parent-reported child language ability evaluation tool are as follows. All participants met the following criteria: 1) After being born in South Korea or English-speaking countries, Korean was spoken as the primary language with caregivers at home, 2) have lived in English-speaking countries for at least one year during the language developing period, 3) attend preschool or kindergarten which English is a primary language in English speaking countries, 4) have no history of parental concern including hearing impairment, cognitive delays, or neurological deficits regarding their language development. The subjects’ consistent and meaningful exposure to the second language averaged 35.8 months. At the time of the survey, the subjects’ average daily exposure to English was 7.19 hours per day, ranging from 4 hours per day for the least exposed children to 16 hours per day for the most exposed children. Fourteen subjects reported using English as the primary language with their friends, while two children communicated by mixing Korean vocabulary with English sentences. Three children primarily used their native language when communicating with friends. However, it was noted that all children utilized both their native language and English, indicating that they did not experience significant difficulty in communicating in the second language.

Children were classified based on their language performance. To assess the children’s Korean and English language performance, the Korean receptive and expressive vocabulary test (Kim, Hong, Kim, Chang, & Lee, 2009), Peabody picture vocabulary test-IV (PPVT-IV; Dunn & Dunn, 2007), and expressive one-word picture vocabulary test-IV (EOWPVT-IV; Martin & Brownell, 2010) were used. Since bilingual children exposed to diverse cultural and linguistic environments can be excessively diagnosed with language impairment (Kayser, 1995; Langdon, 1992), conceptual scoring was used to consider children’s language ability (Yim, Chung, Han, Baek, & Lim, 2022).

All participants with LD met the following criteria: (a) Korean receptive or expressive conceptual score is below -1.25 SD, (b) English receptive or expressive conceptual score is below 14%ile, (c) scored -1 SD (85) higher on the nonverbal scale of Kaufman brief intelligence test-second edition. All participants with TD met the following criteria: (a) above -1 SD in conceptual score among three of four language tests (Korean and English receptive and expressive test), (b) scored -1 SD (85) higher on the nonverbal scale of Kaufman brief intelligence test-second edition. The non-verbal scale did not differ significantly across groups (LD: M=104.67, SD=21.28, TD: M=106.30, SD=11.75). The t-test results for the participants’ chronological age, nonverbal scale, and Korean and English receptive and expressive scores by group are presented in Table 1.

Table 1.

Mean performance and differences on the language test used for a group classification

Measures and Materials

Language proficiency assessment task

To assess the children’s proficiency in both Korean and English, the Korean receptive and expressive vocabulary test (REVT; Kim et al., 2009), the Peabody picture vocabulary test-IV (PPVT-IV; Dunn & Dunn, 2007), and the expressive one-word picture vocabulary test-IV (EOWPVT-IV; Martin & Brownell, 2010) were utilized. To verify the presence of vocabulary concepts in the children’s lexicon, each test began with the first question, with the ceiling point established when children provided incorrect responses to Korean and English words (Bedore, Peña, García, & Cortez, 2005; Pearson, Fernández, & Oller, 1993).

For conceptual scoring, the Korean Receptive Vocabulary Test (REVT-R; Kim et al., 2009) and the English Receptive Vocabulary Test (PPVT-IV; Dunn & Dunn, 2007) used translations from previous studies (Yim et al., 2022). The Korean expressive vocabulary test (REVT-E; Kim et al., 2009) and the English expressive vocabulary test (EOWPVT-IV; Martin & Brownell, 2010) were translated into different languages. The task validity of both tests was confirmed as follows: First, vocabulary translation was conducted based on dictionary meanings. Two students who completed coursework in a master’s program in speech-language pathology, including a researcher, recorded translations from the first to the maximum third meaning provided by the Naver dictionary (http://dict.naver.com). Each translation was limited to a single word. Next, each question’s corresponding picture was presented to two native English speakers with at least five years of experience in early childhood education institutions in English-speaking countries. The correspondence between the translated vocabulary and their response was evaluated using the fill-in-the-blank method and by assessing their answers to questions. In the third stage, two master’ s students with a second-level language rehabilitation certificate in Korean speech-language pathology, along with a bilingual individual fluent in Korean-English and holding an English-speaking national language rehabilitation certificate, assessed the appropriateness of the translation based on the results of the second stage.

Narrative task

The multilingual assessment instrument for narratives (MAIN; Gagarina et al., 2019) was used to assess children’s narrative abilities before and after intervention. MAIN is designed to evaluate the narrative skills of children exposed to multiple languages from birth. Based on a preliminary study involving 550 monolingual and bilingual children, MAIN measures and analyzes story comprehension and expression abilities in children aged 3-10 years. This tool is particularly suited for children from culturally and linguistically diverse backgrounds. MAIN comprises four stories (Cat, Dog, Baby Birds, Baby Goats), each illustrated with six pictures. Each study focuses on a single character and is structured around five key SG elements: initiating events, internal reactions, attempts, outcomes, and endings. In this study, ‘Cat’ and ‘Dog’ stories were utilized to collect pre-narratives, while ‘Baby Birds’ and ‘Baby Goats’ were used for post-narratives. The analysis of the SG in English narratives utilized the scoring sheet provided by MAIN (Gagarina et al., 2019). An original scoring sheet was developed to analyze the Korean narrative SG. Due to copyright concerns, only a representative image is presented in Figure 1.

Figure 1.

An example of a multilingual assessment instrument for narratives (MAIN; Gagarina et al., 2019).

The task validity of the revised version was confirmed through the following process: Initially, a researcher who completed coursework in a master’s program in speech-language pathology translated it into English. In the second stage, a bilingual individual fluent in Korean-English, holding an English-speaking national language rehabilitation certificate, and currently enrolled in a master’s program in speech-language pathology in Korea, reviewed the translation to assess the appropriateness of content adaptation. In the third stage, the validity and reliability of the adaptation were confirmed by a language therapist with a master’s degree in speech-language pathology, along with two speech-language pathologists holding first-degree language rehabilitation certificates. Additionally, the reliability of the adaptation was further confirmed by a professor of speech-language pathology.

Narrative intervention program

The intervention program utilized in this study, Story Champs^® 2.0 (Spencer & Petersen, 2016), was adapted for use in Korean, employing an organized method that reflects the SG structure outlined by Stein and Glenn (1979). Each intervention session utilized the online digital presentation provided by Story Champs. Story Champs is a structured intervention program designed to teach SG structures to children of all ages, facilitating the acquisition of linguistically complex elements in the process. Each story incorporates five essential components of SG: character, initiation, internal reaction, attempt, and ending. The program employs a method that initially presents and gradually removes icons to aid children in comprehending both the story’s picture and grammar. This process follows the mediator modeling the story based on the individualized intervention strategy outlined in the program, followed by three retellings of the story. The protocol was implemented by selecting a protocol from the Story Champs’ manuals.

Each intervention cycle comprises four steps. Initially, the interventionist presents five illustrations on screen and reads the story translated into Korean. Simultaneously, the interventionist places SG icons-character, problem, feeling, action, and ending- on the illustrations while narrating the story. After the modeling, the interventionist leaves the illustrations and icons on the screen and prompts the child to retell the story. Corrections or expansions are provided immediately by the interventionist in response to any errors the child makes during the retelling. After the child retells the story with the illustrations and icons, the interventionist removes the illustration but leaves the icon in place. The child is then prompted to retell the story again, with the option to receive assistance from the interventionist in the same manner as in the previous stage. In the final stage, the interventionist removes the icons, prompting the child to retell the story without illustrations or icons. Unlike previous stages, the final stage does not involve correcting errors the child makes.

If a child encounters difficulty speaking during the mediation process, the interventionist utilizes 4-step prompts to assist children in successfully retelling stories (Petersen et al., 2016). After the mediator models the storytelling process, the supportive cues gradually diminish, and the child is prompted to retell the story three times. During this stage, if the child encounters difficulty in storytelling, the mediator employs a four-step facilitation strategy to aid the child in narrative expression. The facilitation strategies are administered as follows.

Step 1, Prompts are provided by asking indirect questions (e.g., “Then what happened?”-“다음에 무슨 일이 일어났어?”), which is considered the least restrictive approach.

Step 2, The interventionist gives direct questions (e.g., Who was the story about? Why was he sad?-누구에 대한 이야기였어? 민수의 기분은 어땠을까?”) and provides direct prompts about the target SG elements (e.g., “You need to tell me about the problems.”- “여기에서 무슨 일이 일어났어요?”).

Step 3, The interventionist uses cloze procedures prompts (e.g., “Minsu fell and hurt his knee. Now he felt________. Minsu was sad (why?) ________.”- “민수가 넘어져서 무릎을 다쳤어. 그래서 민수는 기분이…. 민수는 슬펐어 왜냐하면….”).

Step 4. The most restrictive prompts are given, involving modeling of targets (e.g., “He felt sad because he got hurt. Now you say that.”-“민수는 다쳐서 슬펐어. 선생님 따라해보자.”)

Adapting the story in the intervention program into Korean followed a structured process. Initially, a researcher who completed coursework in speech-language pathology at the master’s level undertook the adaptation of the Story Champs narrative. Subsequently, in the second step, the validity and reliability of the adaptation were assessed by a first-grade language rehabilitation speech-language pathologist proficient in both Korean and English, alongside an English-speaking national language rehabilitation speech-language pathologist. Finally, the reliability of the adaptation was confirmed by a professor of speech-language pathology who was fluent in both Korean and English. Due to copyright concerns, only a representative image is presented in Figure 2 and a story translated into Korean is provided in Appendix 1.

Figure 2.

An example of an online digital presentation in the story champs (Spencer & Petersen, 2016).

RESULTS

Intervention Efficacy in Korean

The performance of the Korean narrative for children with and without LD is presented in Table 2.

Table 2.

Means and standard deviation for narrative performance in Korean

Story grammar

A two-way mixed ANOVA was conducted to examine the differences in SG performance between time (pre- vs. post-) and group (LD vs. TD). The main effect of time was significant (F_{(1, 17)}=11.108, p<.05). However, the main effect of group was not statistically significant (F_{(1, 17)}=.416, p>.05), nor was the Group* Time interaction (F_{(1, 17)}=.327, p>.05).

The number of different words

A two-way mixed ANOVA was conducted to examine the differences in the number of words between time (pre- vs. post-) and group (LD vs. TD). The main effect of time was significant (F_{(1, 17)}=14.613, p<.05). However, the main effect of group was not statistically significant (F_{(1, 17)}=.49, p>.05), nor was the Group* Time interaction (F_{(1, 17)}=.423, p>.05).

The mean length of utterance-words

There were non-normal distributions for the MLUw in Korean, as confirmed by the Shapiro-Wilk test. Due to the non-normal distribution, the Mann-Whitney U test was conducted to identify differences in MLUw between pre-and post-intervention results. In the pre-test, the TD group generated higher MLUw (Z=6.08, quartile=5.51) than the LD group (Z=5.56, quartile =4.61); however, there was no statistical difference between the groups (Z=-.941, p>.05). In the post-test, the TD group again generated higher MLUw (Z=7.05, quartile=6.45) than the LD group (Z=6.92, quartile =6.06). However, there were no significant differences between the groups (Z=-.082, p>.05).

Wilcoxon signed-ranks tests were conducted to compare MLUw’s pre-and post-test scores. The results revealed a significant difference between pre-and post-intervention results in both the LD group (Z=-2.547, p<.05), and the TD group (Z=-2.497, p<.05). Therefore, it can be interpreted that the Korean MLUw of both groups of children significantly improved after the intervention compared to before the intervention.

Cross-linguistic Influence from Korean to English

The performance of narrative in English, attributed to cross-linguistic influence for children with and without LD, is presented in Table 3. To compare the difference in narrative performance between the LD and TD groups on each measure of SG, NDW, and MLUw, a two-way mixed ANOVA was conducted with ‘time’ (pre- vs. post-) as a within-subjects factor and ‘group’ (LD vs. TD) as a between-subjects factor.

Table 3.

Means and standard deviation for narrative performance in English

Story grammar

The results indicated that the main effect between groups was not significant (F_{(1, 17)}=.032, p>.05). However, there was a significant main effect for time (F_{(1, 17)}=7.239, p<.05). In other words, both LD and TD groups made significantly greater gains on the post-test (M=8.14, SD=2.86) compared to the pre-test (M=6.59, SD=1.85). The Group* Time interaction was not significant (F_{(1, 17)}=.911, p>.05).

The number of different words

The results indicated that the main effect between groups was not significant (F_{(1, 17)}=.034, p>.05). However, there was a significant main effect for time (F_{(1, 17)}=6.573, p<.05). In other words, both LD and TD groups made significantly greater gains on the post-test (M=22.09, SD=9.16) compared to the pre-test (M=28.43, SD=11.89). The Group×Time interaction was not significant (F_{(1, 17)}=.034, p>.05).

The mean length of utterance-words

The results indicated that the main effect was not significant between groups (F_{(1, 17)}=2.511, p>.05) or for time (F_{(1, 17)}=.972, p>.05). The Group×Time interaction was also not found (F_{(1, 17)}=.142, p>.05).

Correlational Analysis: Vocabulary Skills and Narrative

Table 4 displays the results of the correlational analysis for all Korean-English bilingual children. First, Korean MLUw in the pre-test was positively correlated with all vocabulary skills, including Korean expressive vocabulary skills (r=.662, p<.01), Korean receptive vocabulary skills (r=.582, p<.01), English expressive vocabulary skills (r=.472, p<.05), and English receptive vocabulary skills (r=.468, p<.05).

Table 4.

Correlations among vocabulary skills in Korean and English, and pre- and post-narrative skills in Korean and English

Among the narrative results in the post-test, Korean expressive vocabulary skills were positively correlated with English SG (r=.514, p<.05) and English MLUw (r=.590, p<.01). Additionally, English expressive vocabulary skills were positively correlated with English MLUw (r=.530, p<.05).

DISCUSSION

In this study, we first aimed to determine whether a 15-minute Korean (L1) narrative intervention would lead to a significant increase in both macro and micro-level performance in Korean narrative among Korean-English bilingual children. The results showed a statistically significant difference in the gains of the Korean SG, NDW, and MLUw between the pre-and post-test, indicating that narrative intervention in L1 effectively enhanced their L1 narrative skills in both macro- and microstructure. This finding is consistent with previous research demonstrating the efficacy of narrative intervention in improving children’s narrative performance, including SG, NDW, and communication units (Armon-Lotem, Rose, & Altman, 2021; Schoenbrodt et al., 2003). Furthermore, previous studies have reported the efficacy of narrative intervention with Spanish-English bilingual children, who exhibit a higher degree of language typology (Schoenbrodt et al., 2003). Thus, our research suggests that narrative intervention is a valuable approach for improving the narrative skills of children whose languages have a lower degree of typological similarity, such as Korean and English.

On the other hand, there was no statistically significant difference between the LD and TD groups across the macro- and microstructure (SG, NDW, and MLUw). These results differ from previous studies that confirmed significant differences in narrative skills, including NDW and MLUw, between TD and LD bilingual children (Kapantzoglous et al., 2017; Simon-Cereijido & Gutierrez-Clellen, 2009). Hence, we also analyzed utterance errors in children’s pre- and post-narrative performances in both Korean and English. Further details can be found in Appendix 3. The results revealed differences in error rates between groups, particularly in Korean suffix and particle errors. These findings suggest that the narrative task employed in this experiment may not have provided sufficient detail for analyzing children’s utterances in depth. Furthermore, it may imply considering different factors when evaluating the language abilities of bilingual children based on their L1 and L2. In previous research, MLUw was an important factor in distinguishing TD and LD Spanish-English bilingual children with a high degree of typological similarity between the two languages (Kapantzoglous et al., 2017; Simon-Cereijido & Gutierrez-Clellen, 2009). However, in this study, SG, NDW, and MLUw did not show statistically significant differences between the groups with lower typological similarity. Additionally, SG has been identified as a distinguishing factor between TD children and language-delayed children from various cultural backgrounds learning English as a second language, but not in Russian (L1)-Hebrew (L2) bilingual children with and without specific language impairment (Fichman, Altman, Voloskovich, Armon-Lotem, & Walters, 2017). Therefore, qualitative factors such as error analysis should be considered when evaluating the language abilities of Korean-English bilingual children (Hong & Yim, 2019; Park, Park, & Seok, 2007).

The second research question addressed whether there was cross-linguistic transfer to the language that was not intervened in. The findings showed no significant differences between the LD and TD groups in SG, NDW, and MLUw. This suggests that the lack of substantial differences in both L1 and L2 performances between TD and LD groups may influence the results of cross-linguistic transfer. Additionally, it implies that when assessing the cross-linguistic transfer effect in Korean-English bilingual children, other factors may need to be considered to differentiate between groups effectively. However, statistically, significant differences were found in SG and NDW before and after the intervention. These results align with previous research, specifically the only narrative intervention study for bilingual children found by the researcher. In that study, TD Spanish-English bilingual children in the treatment group made significantly greater gains from pre- to post-test compared to the control group. However, children with language impairments in both the treatment and control groups did not show significantly different interactions (Petersen et al., 2016). This suggests that intervention in children’s L1 has a partial mediating effect on the L1 and a transfer effect on the L2 in terms of SG and NDW. These results are consistent with previous studies demonstrating the transfer effect of L1 intervention on L2 in bilingual children (Armon-Lotem et al., 2021; Gutiereez-Clellen, 1999; Peña & Kester, 2004; Thordardottir et al., 1997). Furthermore, previous research suggests that L1 intervention can be expected to have long-term effects on L2 (Baker, 2000; Coltrane, 2003; Cummins, 2000). Unlike previous studies focusing on Spanish-English bilingual children, these clinical findings suggest that the transfer effect of L1 intervention is observable in Korean-English bilingual children, even considering the low typological similarity between the two languages.

Finally, we examined the correlation between vocabulary skills and narrative abilities in Korean and English. The results indicated a correlation between MLUw in Korean during the pre-test and both receptive and expressive vocabulary in both Korean and English. However, in the post-test, a significant correlation was observed between Korean expressive vocabulary and English SG, as well as between Korean expressive vocabulary and English MLUw. Furthermore, a significant correlation was observed between English expressive vocabulary and English MLUw. These results align with previous studies demonstrating a significant correlation between the depth of L1 language proficiency, including superordinate vocabulary, and L2 proficiency, particularly in individuals with limited L2 vocabulary skills, as evidenced in prior research (Ordóñez, Carlo, Snow, & McLaughlin, 2002). Thus, it can be inferred that the child’s proficiency in L2 vocabulary is significantly correlated with their performance in L2. Moreover, these findings reinforce previous research by highlighting the significance of L1 vocabulary proficiency in children within a subtractive bilingual environment (Ordóñez et al., 2002).

In conclusion, the study results suggest that narrative intervention appears effective in enhancing both macro-structure aspects, such as SG, and micro-structure components, including the NDW and mean length of utterance-word. Furthermore, our findings indicate that the intervention conducted in children’s L1 exhibits cross-linguistic influence from the home language (L1) to the school language (L2). Finally, we observed a significant correlation between children’s Korean expressive vocabulary and pre-test mean length of utterance-word in both Korean and English, as well as post-test English SG and mean length of utterance-word. These findings suggest that children’s L1 expressive vocabulary plays a crucial role in facilitating cross-linguistic transfer effects.

The limitations of this study and suggestions for future research are as follows. First, this study identified group differences based on children’s vocabulary proficiency using standardized L1 and L2 composite scoring tests. However, no statistically significant differences were found in the narrative abilities of children between groups. Therefore, future studies should include additional factors, such as discourse analysis, to accurately differentiate children’s language abilities and vocabulary proficiency. This would allow for more generalizable research on preschool bilingual children.

Secondly, this study collected narrative samples through a structured storytelling task. As no significant differences in narrative abilities were found between the pre-and post-tests for the LD and TD groups, we analyzed the error rates in the children’s speech before and after the intervention to identify any differences between the groups. However, because the analysis used the minimum number of utterances as the criterion, the number of speech samples analyzed was limited. Children who produced longer utterances may not have had their speech error rates accurately reflected. Hence, in future studies, analyzing children’s speech in detail, encompassing both spontaneous speech situations and structured tasks, may reveal more sensitive factors for evaluating the language abilities of Korean-English bilingual children.

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