Developmental language disorder (DLD; 7% prevalence), defined by low language despite otherwise normal development, puts children at greater risk for reading problems and lower vocational attainment (Bishop et al., 2017).
Our research lab is pioneering the study of DLD for the Vietnamese language. An overall goal of this project is to create effective tools in Vietnamese that will confirm the presence or absence of DLD at the individual level, whether a child is learning Vietnamese alone or in combination with English.
Data collection will be with bilingual children in the United States and monolingual children in Vietnam. Findings will improve assessment accuracy of DLD for Vietnamese speakers worldwide. If you are interested in having your child participate in this study or any of our other projects, visit our Participate in Projects page!
Funding: National Institutes of Health – National Institute on Deafness and Other Communication Disorders (NIH-NIDCD R01DC019335)
What have we done so far?
Last updated: August 5, 2025
- We have administered 11 assessment tasks to about 350 children in Vietnam and the United States since 2021. Approximately 200 children were monolingual Vietnamese children from Hanoi, Vietnam, aged 4–6, and 150 were bilingual Vietnamese-English children across the United States.
What have we learned?
Last updated: August 5, 2025
- Our Vietnamese Sentence Repetition task can contribute to accurate DLD identification in monolingual Vietnamese children. We optimized the Vietnamese sentence repetition task by reducing the number of items and evaluating its diagnostic properties. Primary outcomes include two different sentence repetition tools: full assessment (28 items) and screening (14 items). Full results can be found in Pham, Choi Tucci, Do, & Ebert, 2025.
- Vietnamese classifiers have the potential to serve as an indicator of disorder. Vietnamese monolingual children with DLD make more errors when producing classifiers; they use fewer different types of classifiers and are more restricted in how they use classifiers in sentence structures. Full results can be found in a qualitative analysis of classifier use (Pham & Simpson, 2024) and a longitudinal study (Pham, Simpson, & Nguyen, 2023).
What do we still need to do?
Last updated: August 5, 2025
- We are still recruiting bilingual Vietnamese-English children to strengthen our research findings. If you are interested in having your child participate in this study, apply here!
- We are comparing four groups of Vietnamese-speaking children (bilinguals/monolinguals, with/without DLD) to understand their language development. This will support our search for indicators of DLD in Vietnamese.
- We will determine how professionals outside of research implement these tasks and how we can support them. For now, you can visit VietSLP for additional clinical resources.