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In:Acquisition of Korean: The state of the art
Edited by Soonja Choi
[Trends in Language Acquisition Research 36] 2026
► pp. 292–321

Chapter 9
Assessing morphosyntactic complexity in child L2 learners of Korean

Exploring the roles of internal and external factors

 | Yonsei University
 | Seoul National University
 | Gyeongin National University of Education
 | The Chinese University of Hong Kong
This content is being prepared for publication; it may be subject to changes.
Abstract
This chapter investigates morphosyntactic complexity in child second language (L2) learners of Korean, examining the roles of internal and external factors. Korean’s rich morphology provides an ideal context for exploring how bilingual children develop grammatical skills. Sixty-eight bilingual children (L1 Chinese or Russian) completed an oral picture-narration task. Two complexity indices — morpheme diversity and particle types per sentence — were analyzed. Regression analyses revealed distinct predictors for each index. Morpheme diversity was significantly associated with length of Korean exposure and working memory, with L2 use with parents emerging as the strongest environmental predictor. In contrast, particle types per sentence were primarily predicted by L2 interaction in social contexts beyond home and school. These findings highlight the combined impact of cognitive capacities and diverse interactional experiences on L2 morphosyntactic development in Korean-learning bilingual children, underscoring the need to consider both individual and contextual factors in understanding L2 grammatical growth.
Article outline
  • 1.Introduction
  • 2.Roles of learner-internal factors in L2 morphosyntactic development
  • 3.Roles of learner-external factors in L2 morphosyntactic development
  • 4.The present study
  • 5.Method
    • 5.1Participants
    • 5.2Learner-internal variables
    • 5.3Environmental variables
    • 5.4Dependent variables: Morphosyntactic complexity
      • 5.4.1Task design
      • 5.4.2Background on the importance of counting grammatical morphemes in Korean
      • 5.4.3Measurement of morpheme diversity
      • 5.4.4Measurement of the number of particle types per sentence
    • 5.5Data analysis
  • 6.Results
    • 6.1Diversity of morphemes
    • 6.2Number of particle types per sentence
  • 7.Discussion
    • 7.1Variables influencing the diversity of morphemes
    • 7.2Variables influencing the number of particle types per sentence
    • 7.3Implications and directions for further research
  • Author queries
  • Notes
  • References
References (72)
References
Ahn, H. (2015). Second language acquisition of Korean case by learners with different first languages (Doctoral dissertation. University of Washington. ProQuest Dissertations and Theses Global (Publication No. 1722049012).
Anderson, M. C. (2003). Rethinking interference theory: Executive control and the mechanisms of forgetting. Journal of Memory and Language, 49, 415–445. Google Scholar logo with link to Google Scholar
Bialystok, E., & Hakuta, K. (1999). Confounded age: Linguistic and cognitive factors in age differences for second language acquisition. In D. Birdsong (Ed.), Second language acquisition and the Critical Period Hypothesis (pp. 161–181). Lawrence Erlbaum Associates.Google Scholar logo with link to Google Scholar
Birdsong, D. (2006). Age and second language acquisition and processing: A selective overview. Language Learning, 56, 9–49. Google Scholar logo with link to Google Scholar
(2009). Age and the end state of second language acquisition. In W. Ritchie & T. Bhatia (Eds.), The new handbook of second language acquisition (pp. 401–424). Elsevier.Google Scholar logo with link to Google Scholar
Bosch, S., Veríssimo, J., & Clahsen, H. (2019). Inflectional morphology in bilingual language processing: An age-of-acquisition study. Language Acquisition, 26, 339–360. Google Scholar logo with link to Google Scholar
Bulté, B., & Housen, A. (2012). Defining and operationalising L2 complexity. In A. Housen, F. Kuiken, & I. Vedder (Eds.), Dimensions of L2 performance and proficiency: Complexity, accuracy and fluency in SLA (pp. 21–46). John Benjamins. Google Scholar logo with link to Google Scholar
Cho, S., Lee, M., O’Grady, W., Song, M., Suzuki, T., & Yoshinaga, N. (2002). Word order preferences for direct and indirect objects in children learning Korean. Journal of Child Language, 29, 897–909. Google Scholar logo with link to Google Scholar
Choo, M., & Kwak, H.-Y. (2008). Using Korean: A guide to contemporary usage. Cambridge University Press. Google Scholar logo with link to Google Scholar
Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Lawrence Erlbaum Associates.Google Scholar logo with link to Google Scholar
Conway, A. R. A., Jarrold, C., Kane, M. J., Miyake, A., & Towse, J. N. (2007). Variation in working memory. Oxford University Press.Google Scholar logo with link to Google Scholar
DeKeyser, R., & Larson-Hall, J. (2005). What does the critical period really mean? In J. F. Kroll & A. M. B. de Groot (Eds.), Handbook of bilingualism: Psycholinguistic approaches (pp. 88–108). Oxford University Press.Google Scholar logo with link to Google Scholar
Dörnyei, Z. (2014). The psychology of the language learner: Individual differences in second language acquisition. Routledge. Google Scholar logo with link to Google Scholar
Eslami, Z., & Ahn, S. J. (2014). Motivation, amount of interaction, length of residence, and ESL learners’ pragmatic competence. Applied Research on English Language, 3, 9–28.Google Scholar logo with link to Google Scholar
Frenck-Mestre, C., Choo, H., Zappa, A., Herschensohn, J., Kim, S. K., Ghio, A., & Koh, S. (2022). The online processing of Korean case by native Korean speakers and second language learners as revealed by eye movements. Brain Sciences, 12, 1230. Google Scholar logo with link to Google Scholar
Gangopadhyay, I., Davidson, M. M., Weismer, S. E., & Kaushanskaya, M. (2016). The role of nonverbal working memory in morphosyntactic processing by school-aged monolingual and bilingual children. Journal of Experimental Child Psychology, 142, 171–194. Google Scholar logo with link to Google Scholar
Govindarajan, K., & Paradis, J. (2019). Narrative abilities of bilingual children with and without Developmental Language Disorder (SLI): Differentiation and the role of age and input factors. Journal of Communication Disorders, 77, 1–16. Google Scholar logo with link to Google Scholar
Granena, G., & Long, M. H. (2013). Age of onset, length of residence, language aptitude, and ultimate L2 attainment in three linguistic domains. Second Language Research, 29, 311–343. Google Scholar logo with link to Google Scholar
Green, D. W. (1986). Control, activation, and resource: A framework and a model for the control of speech in bilinguals. Brain and Language, 27, 210–223. Google Scholar logo with link to Google Scholar
(1998). Schemas, tags and inhibition. Bilingualism: Language and Cognition, 1, 100–104. Google Scholar logo with link to Google Scholar
Grosjean, F. (2013). Bilingual and monolingual language modes. In C. Chapelle (Ed.), The encyclopedia of applied linguistics (pp. 489–493). Wiley-Blackwell.Google Scholar logo with link to Google Scholar
Grüter, T., Hurtado, N., Marchman, V. A., & Fernald, A. (2014). Language exposure and online processing efficiency in bilingual development: Relative versus absolute measures. In T. Grüter & J. Paradis (Eds.), Input and experience in bilingual development (pp. 15–36). John Benjamins. Google Scholar logo with link to Google Scholar
Hartshorne, J. K., Tenenbaum, J. B., & Pinker, S. (2018). A critical period for second language acquisition: Evidence from 2/3 million English speakers. Cognition, 177, 263–277. Google Scholar logo with link to Google Scholar
Hoff, E. (2006). How social contexts support and shape language development. Developmental Review, 26, 55–88. Google Scholar logo with link to Google Scholar
Hong, W. P. (2010). Multicultural education in Korea: Its development, remaining issues, and global implications. Asia Pacific Education Review, 11, 387–395. Google Scholar logo with link to Google Scholar
Hwang, H. (2024). Development of morphological diversity in second language Korean: An NLP analysis using the Korean Morphological Richness Analyzer 1.0. System, 121, 103260. Google Scholar logo with link to Google Scholar
Hwang, H., & Kim, H. (2024). Korean Syntactic Complexity Analyzer (KOSCA): An NLP application for the analysis of syntactic complexity in second language production. Language Testing, 41, 506–529. Google Scholar logo with link to Google Scholar
Ji, H. S. (2006). The error analysis of spoken grammar in Korean interview tests. Journal of Korean Language Education, 17, 301–323.Google Scholar logo with link to Google Scholar
Jia, G., & Aaronson, D. (2003). A longitudinal study of Chinese children and adolescents learning English in the United States. Applied Psycholinguistics, 24, 131–161. Google Scholar logo with link to Google Scholar
Jia, G., & Fuse, A. (2007). Acquisition of English grammatical morphology by native Mandarin speaking children and adolescents: Age-related differences. Journal of Speech, Language, and Hearing Research, 50, 1280–1299. Google Scholar logo with link to Google Scholar
Johnson, J. S., & Newport, E. L. (1989). Critical period effects in second language learning: The influence of maturational state on the acquisition of English as a second language. Cognitive Psychology, 21, 60–99. Google Scholar logo with link to Google Scholar
Kim, K. (2014). Unveiling linguistic competence by facilitating performance (Doctoral dissertation). University of Hawai‘i at Mānoa. ProQuest Dissertations and Theses Global (Publication No. 1611733258).
Kim, K., & Kim, H. (2022). Sequential bilingual heritage children’s L1 attrition in lexical retrieval: Age of acquisition versus language experience. Bilingualism: Language and Cognition, 25, 537–547. Google Scholar logo with link to Google Scholar
Kim, K., O’Grady, W., & Schwartz, B. D. (2018). Case in heritage Korean. Linguistic Approaches to Bilingualism, 8, 252–282. Google Scholar logo with link to Google Scholar
Kim, M. (2020). From connective construction to final particle: The emergence of the Korean disapproval marker hakonun. Linguistics, 58, 1581–1607. Google Scholar logo with link to Google Scholar
Kim, S., O’Grady, W., & Cho, S. (1995). The acquisition of case and word order in Korean: A note on the role of context. Language Research, 31, 687–695.Google Scholar logo with link to Google Scholar
Köpke, B., & Schmid, M. S. (2004). Language attrition: The next phase. In B. Köpke, M. S. Schmid, M. Keijzer, & L. Weilemar (Eds.), First language attrition: Interdisciplinary perspectives on methodological issues (pp. 1–46). John Benjamins. Google Scholar logo with link to Google Scholar
Leeser, M. J., & Sunderman, G. (2016). Methodological implications of working memory tasks for L2 processing research. In G. Granene, D. Jackson & Y. Yilmaz (Eds.), Cognitive individual differences in second language processing and acquisition (pp. 89–104). Amsterdam: John Benjamins. Google Scholar logo with link to Google Scholar
Lenneberg, E. (1967). Biological foundations of language. John Wiley.Google Scholar logo with link to Google Scholar
Linck, J. A., Osthus, P., Koeth, J. T., & Bunting, M. F. (2014). Working memory and second language comprehension and production: A meta-analysis. Psychonomic Bulletin & Review, 21, 861–883. Google Scholar logo with link to Google Scholar
Long, M. (1990). Maturational constraints on language development. Studies in Second Language Acquisition, 12, 251–285. Google Scholar logo with link to Google Scholar
(2013). Maturational constraints on child and adult SLA. In G. Granena & M. Long (Eds.), Sensitive periods, language aptitude, and ultimate L2 attainment (pp. 3–42). John Benjamins. Google Scholar logo with link to Google Scholar
MacIntyre, P. D., & Gardner, R. C. (1991). Language anxiety: Its relationship to other anxieties and to processing in native and second languages. Language Learning, 41, 513–534. Google Scholar logo with link to Google Scholar
(2009). Reexamining the fundamental difference hypothesis: What can early bilinguals tell us? Studies in Second Language Acquisition, 31, 225–257. Google Scholar logo with link to Google Scholar
Mueller, S. T., & Piper, B. J. (2014). The psychology experiment building language (PEBL) and PEBL test battery. Journal of Neuroscience Methods, 222, 250–259. Google Scholar logo with link to Google Scholar
Páez, M. M., Tabors, P. O., & López, L. M. (2007). Dual language and literacy development of Spanish-speaking preschool children. Journal of Applied Developmental Psychology, 28, 85–102. Google Scholar logo with link to Google Scholar
Paradis, J., Rusk, B., Sorenson Duncan, T., & Govindarajan, K. (2017). Children’s second language acquisition of English complex syntax: The role of age, input and cognitive factors. Annual Review of Applied Linguistics, 37, 1–20. Google Scholar logo with link to Google Scholar
Place, S., & Hoff, E. (2016). Effects and noneffects of input in bilingual environments on dual language skills in 2 1/2-year-olds. Bilingualism: Language and Cognition, 19, 1023–1041. Google Scholar logo with link to Google Scholar
Portner, P., Pak, M., & Zanuttini, R. (2022). Dimensions of honorific meaning in Korean speech style particles. Glossa: A Journal of General Linguistics, 7, 1–33.Google Scholar logo with link to Google Scholar
Prevoo, M. J. L., Malda, M., Mesman, J., Emmen, R. A. G., Yeniad, N., Van Ijzendoorn, M. H., & Linting, M. (2014). Predicting ethnic minority children’s vocabulary from socioeconomic status, maternal language and home reading input: Different pathways for host and ethnic language. Journal of Child Language, 41, 963–984. Google Scholar logo with link to Google Scholar
R Core Team. (2023). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. [URL]
Rojas, R., Iglesias, A., Bunta, F., Goldstein, B., Goldenberg, C., & Reese, L. (2016). Interlocutor differential effects on the expressive language skills of Spanish-speaking English learners. International Journal of Speech-Language Pathology, 18, 166–177. Google Scholar logo with link to Google Scholar
Scheele, A., Leseman, P., & Mayo, A. (2010). The home language environment of monolingual and bilingual children and their language proficiency. Applied Psycholinguistics, 31, 117–140. Google Scholar logo with link to Google Scholar
Schmid, M. S., & Dusseldorp, E. (2010). Quantitative analyses in a multivariate study of language attrition: The impact of extralinguistic factors. Second Language Research, 26, 125–160. Google Scholar logo with link to Google Scholar
Shin, S. C. (2016). English L1-Korean L2 learners’ cognitive knowledge and difficulty of grammatical error items. Language Facts and Perspectives, 37, 173–201. Google Scholar logo with link to Google Scholar
Slabakova, R. (2013). What is easy and what is hard to acquire in a second language: A generative perspective. In M. del P. García Mayo, M. J. Gutiérrez Mangado, & M. Martínez-Adrián (Eds.), Contemporary approaches to second language acquisition (pp. 5–28). John Benjamins. Google Scholar logo with link to Google Scholar
Sohn, H. M. (2001). The Korean language. Cambridge University Press.Google Scholar logo with link to Google Scholar
Song, H. S., & Schwartz, B. D. (2009). Testing the fundamental difference hypothesis: L2 adult, L2 child, and L1 child comparisons in the acquisition of Korean wh-constructions with negative polarity items. Studies in Second Language Acquisition, 31, 323–361. Google Scholar logo with link to Google Scholar
Sorenson Duncan, T., & Paradis, J. (2020a). Home language environment and children’s second language acquisition: The special status of input from older siblings. Journal of Child Language, 47, 982–1005. Google Scholar logo with link to Google Scholar
(2020b). How does maternal education influence the linguistic environment supporting bilingual language development in child second language learners of English? International Journal of Bilingualism, 24, 46–61. Google Scholar logo with link to Google Scholar
Statistics Korea. (2020). Vital statistics of immigrants in 2020. [URL]
Tabachnick, B. G., & Fidell, L. S. (2013). Using multivariate statistics (6th ed.). Pearson Education.Google Scholar logo with link to Google Scholar
Unsworth, S. (2013). Assessing the role of amount and timing of exposure in simultaneous bilingual development and ultimate attainment. Bilingualism: Language and Cognition, 16, 86–110. Google Scholar logo with link to Google Scholar
(2016). Quantity and quality of language input in bilingual language development. In E. Nicoladis & S. Montanari (Eds.), Lifespan perspectives on bilingualism (pp. 136–196). De Gruyter. Google Scholar logo with link to Google Scholar
Unsworth, S., Brouwer, S., de Bree, E., & Verhagen, J. (2019). Predicting bilingual preschoolers’ patterns of language development: Degree of non-native input matters. Applied Psycholinguistics, 40, 1189–1219. Google Scholar logo with link to Google Scholar
Unsworth, S., Hulk, A., & Marinis, T. (2011). Internal and external factors in child second language acquisition: Introduction. Linguistic Approaches to Bilingualism, 1, 207–212. Google Scholar logo with link to Google Scholar
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