Syntactic complexity in adolescents' elicited and semi-spontaneous speech

This new paper (co-authored with Elliot Holmes) has been accepted for publication in the Journal of Child Language. It is based on research carried out initially with Lydia Gunning and Ekaterini Klepousniotou, as part of the pilot project Assessing core language skills in pre-adolescents in the Born-in-Bradford cohort.

Abstract: 

Little is known of syntactic development during early adolescence. Is complex syntax truly mastered at the beginning of secondary education? Are there differences between the knowledge of complex structures and the ability to use them?

Building on a critical review of the literature on syntactic complexity, we investigate these questions in a sentence repetition task and a narrative task, performed by 126 monolingual and bilingual 11- to-13-year-olds educated monolingually and growing up in areas affected by socioeconomic deprivation in the UK.

We demonstrate substantial individual variation associated with syntactic complexity in both tasks, and propose a novel index of syntactic complexity: the proportion of full subordinate clauses. Combining predictive regression models and random forest analyses, we identify the most important predictors of performance.

Drawing on these exploratory findings, we propose a research program to investigate difficulties associated with complex syntax in this age group. 

De Cat, C. and Holmes, E. (in press) Syntactic complexity in adolescents' elicited and semi-spontaneous speech. Journal of Child Language. 

Using Q-BEx to identify children needing specialist referral

Our study “Using Q-BEx to Identify Risk for Language Impairment in Bilingual Children” has been accepted for publication in the Journal of Speech, Language and Hearing research.

Alternative risk factor indices were derived from the Risk Factor and Proficiency modules differing in the weight and detail given to language proficiency. Our aim was to identify the optimal one to include in the Q-BEx backend calculator (which processes the data into spreadsheets and individual child reports).

Each index was applied to two datasets comprised of five- to eight-year-old children: one with independent diagnosis of Developmental Language Disorder (DLD)/Typical Development (TD) (109 bilingual children tested in France) and one of largely all-comer children (278 bilingual and monolingual children tested in France, the Netherlands, and the United Kingdom). We compared how these alternative indices predicted (likely) DLD/TD status, and structural language outcomes, assessed with LITMUS tools, designed for bilingual children.

Optimal balance of sensitivity and specificity was achieved by an index composed of four equally weighted components (age of first word, age of first sentence, early development concerns, and strongest speaking skills between the child’s languages).

• Clinical Application: The optimal risk factor index is now used by the Q-BEx backend calculator to trigger “Red Flags.” It serves as a first-level screening tool to identify children requiring formal diagnostic assessment via LITMUS or other specialist tools.
• Consistency: The index proved reliable across different linguistic environments and both monolingual and bilingual populations, ensuring objective triage for inclusive research sampling. 

De Cat, C., Tuller, L., Gusnanto, A., Kašćelan, D., Prévost, P., Serratrice, L., & Unsworth, S. (2026). Using Q-BEx to Identify Risk for Language Impairment in Bilingual Children. Journal of Speech, Language, and Hearing Research https://doi.org/10.31234/osf.io/57fyb_v2 (OSF preprint, accepted version)

GALA 2025 plenary talk

 I was deeply honoured to be invited to deliver one of the keynote presentations at the 17th Generative Approaches to Language Acquisition conference (GALA 2025) in Tours. 

Reflections on syntactic complexity, through the lens of adolescent language

This study examines syntactic complexity conceptualised as difficulty experienced by individual language users. It focuses on early adolescence: a stage where core syntax is assumed to be acquired, but there remains an effect of difficulty associated with syntactic complexity. I start by addressing three questions: (1) How is syntactic complexity defined within a generativist perspective? (2) How is it operationalised in language acquisition research? (3) To what extent can the effect of narrow syntax be disentangled from processing effects? I argue that Phase-based complexity (as defined in the Minimalist framework) could help us answer the third question.

The main part of the talk reports on a novel investigation of syntactic complexity effects in young adolescents from socio-economically disadvantaged communities in the UK. Performance was assessed across three complementary tasks: sentence repetition (LITMUS SR), narrative production (LITMUS MAIN), and a purpose-designed reading comprehension task (ARCA). Results reveal substantial inter-individual variability across all three tasks, challenging assumptions about homogeneous syntactic competence in this age group.

The analysis focuses on complexity at the clausal level and on the distinction between phasal and non-phasal subordination. I argue that difficulty patterns in sentence repetition primarily reflect processing capacity constraints rather than core syntactic deficits. In narrative production, distribution patterns of clausal subordination are shown to correlate with lexical diversity, morphosyntactic abilities, and reading comprehension abilities (indexed by the York Assessment of Reading Comprehension). I argue the syntactic complexity of narratives is a manifestation of strategic information management and of the sophistication of discourse representations. The reading comprehension data (from the ARCA) reveal that while figurative language constitutes a more substantial comprehension barrier than syntactic complexity per se, complex syntactic structures can impede the successful interpretation of non-literal meaning when these factors co-occur.

The findings converge on the conclusion that, at adolescence, syntactic complexity functions as a proxy measure for language-mediated information processing demands. This is consistent with the central tenet of the generative approach, according to which narrow syntax is inherently economical. 

How detailed do measures of bilingual language experience need to be? A cost-benefit analysis using the Q-BEx questionnaire

What is the optimal level of questionnaire detail required to measure bilingual language experience? This empirical evaluation compares alternative measures of language exposure of varying cost (i.e., questionnaire detail) in terms of their performance as predictors of oral language outcomes. The alternative measures were derived from Q-BEx questionnaire data collected from a diverse sample of 121 heritage bilinguals (5- to 9-years of age) growing up in France, the Netherlands and the UK. Outcome data consisted of morphosyntax and vocabulary measures (in the societal language) and parental estimates of oral proficiency (in the heritage language). Statistical modelling exploited information theoretic and cross-validation approaches to identify the optimal language exposure measure. Optimal cost-benefit was achieved with cumulative exposure (for the societal language) and current exposure in the home (for the heritage language). The greatest level of questionnaire detail did not yield more reliable predictors of language outcomes.

The preprint is available on the OSF, along with the data and script. This paper was accepted for publication in Bilingualism: Language and Cognition.

Individual language experience determinants of morphosyntactic variation in heritage and attriting speakers of Bosnian and Serbian: A causal inference approach

Using a causal inference approach, we explored the relationships among the language experience determinants of morphosyntactic sensitivity, to identify the factors that indirectly and directly cause its acquisition or maintenance in immigration contexts. We probed the sensitivity to Serbian/Bosnian clitic placement violations with a self-paced listening task, in a diverse group of bilinguals in Norway (n = 71), born to immigrant parents, or having emigrated in childhood or adulthood. The outcomes included a metalinguistic violation detection score and a listening/processing time difference between licit and illicit structures.

Structural Equation Models revealed that literacy (as reading practices) was among the most influential determinants of the ability to detect violations, while Bosnian/Serbian use across contexts and age of bilingualism onset determined violation sensitivity in processing. We identified a significant threshold of societal language (SL) exposure at age 8. Rather than SL exposure before this age precluding bilinguals from developing and maintaining morphosyntactic sensitivity, this threshold seems to reflect a protective effect against attrition which intensifies the later after age 8 SL exposure starts. The length of residence in Norway did not determine attrition, suggesting that heritage and attrited speakers should be considered on a continuum rather than as distinct bilingualism profiles. 

DOI: https://doi.org/10.1075/lab.24016.tom

Unpacking language richness as a predictor of bilingual children’s language proficiency

Bilingual children’s language abilities are influenced by the richness of their language experience, which is typically estimated using parental questionnaires and often expressed as a composite score based on frequency-based variables (e.g., time spent reading). We evaluated whether the composite richness score in the Q-BEx questionnaire was fit for purpose. Data were collected from 173 bilingual children aged between 5 and 8 in three different countries (France, the Netherlands and the UK). Parents completed the Q-BEx questionnaire and children completed proficiency tasks in their societal language. We analysed the predictive power of the original score in comparison to several alternatives, derived using a principal components analysis. We found that (i) these alternatives were no more informative than the original, (ii) scores including interlocutor diversity and proficiency in addition to frequency-based measures fared better, (iii) the latent variables underlying richness were comparable across languages, and (iv) whether SES was included made little difference.

Preprint DOI: https://doi.org/10.31219/osf.io/rquvc

Accepted for publication in the Journal of Child Language (August 2025)

Justice To Youth Language Needs: Human rights undermined by an invisible disadvantage

Language difficulties can be a hidden source of inequalities for young people facing the youth justice system.   youthjusticelanguage.org is a European network funded by COST to bring this to light and inform and influence policy-making and practice. I'm grateful to be part of this important project.