by Zheng Junwei and Valerie P. C. Lim


Stuttering is a motor speech disorder that comprises of behaviours such as repeated movements, fixed postures and superfluous behaviours. While stuttering is easily discernable when the disorder is relatively severe, the dysfluent behaviours may be less distinct and harder to diagnose when the disorder is mild, or when the stuttering has reduced after treatment. This is because there is an overlap between stuttering, and normal disfluencies [1], which children who do not stutter also produce as part of their typical development. In such cases, Speech-Language Therapists (SLT) run the risk of erroneously delaying the start of treatment, or prolonging therapy when it is no longer required.


The differential diagnosis of stuttering in bilingual children can be even more challenging for SLTs. One reason for this is that there is still limited information about the disfluency patterns in typically-developing bilingual children from which to draw appropriate comparisons. Previous research has shown that bilingual English-Spanish speaking children produced more stuttering-like disfluencies (SLDs) than their monolingual peers, and that such SLDs may be more prominent in one language than the other [2]. Such data suggests that the monolingual benchmarks used to diagnose stuttering in monolingual children may not be directly applicable to bilingual children.


Singapore is a multicultural society and many children have exposure to English and Mandarin. Yet, there is no data on disfluencies produced by typically-developing English-Mandarin bilingual children here (or elsewhere). In 2016, we embarked on a study that aimed to evaluate the frequency and type of disfluencies in bilingual children in Singapore (SHS-CIRB Ref 2015/3040; part-funded by SRG-AN #10/2016).



A total of 40 typically-developing English-Mandarin bilingual children are being recruited, comprising of 20 English-dominant and 20 balanced bilingual children. To participate in the study, the children have to be:

  • aged between 5:6 – 6:11
  • of Chinese descent
  • able to understand/speak English and Mandarin
  • without diagnosis of stuttering or other language disorders


All children will undergo receptive and expressive vocabulary assessment, and provide language samples in both languages across two tasks (conversation and narrative). All speech samples will be recorded, transcribed and analysed using the Computerised Language Analysis program for stuttering-like and nonstuttering-like disfluencies (Ambrose & Yairi, 1999). Macrostructural and microstructural linguistic analysis will also be conducted.


Preliminary findings

While this study is ongoing, we present preliminary disfluency data for 6 English-dominant and 6 balanced bilinguals [3, 4]. Singaporean balanced bilingual children were found to produce more SLDs than their English-dominant peers. There was no observed language or task effect, since the SLDs were not significantly greater in either language or task. The frequency of SLDs was found to be higher than reported monolingual benchmarks, but were lower than the reported bilingual ranges for English-Spanish speaking children.



Our preliminary findings reveal some differences with published data [2]. We await completion of our study and will be collaborating with our international research partners so as to provide some guidelines for the differential diagnosis of stuttering in bilingual children.


We have almost reached our participant quota, but still need a few more children to complete our data collection. If you know of any children who fit our research criteria, please contact Dr Valerie Lim at, or Ms Zheng Junwei at



  1. Ambrose, N.G. and E. Yairi, Normative Disfluency Data for Early Childhood Stuttering. J Speech Lang Hear Res, 1999. 42(4): p. 895-909.
  2. Byrd, C., L. Bedore, and D. Ramos, The Disfluent Speech of Bilingual Spanish-English Children: Considerations for Differential Diagnosis of Stuttering. Language, Speech & Hearing Services in Schools (Online), 2015. 46(1): p. 30-43.
  3. Lim, V.P.C., et al., Speech disfluencies in typically-developing bilingual children: A preliminary comparison across language dominance, language and task, in 11th Oxford Dysfluency Conference. 2017: Oxford, UK.
  4. Zheng, J., et al., Comparison of disfluency patterns in Conversation and Narratives in typically-developing English-Mandarin Bilingual Children, in 11th Oxford Dysfluency Conference. 2017: Oxford, UK.

Valerie has more than 20 years of experience working in the field of stuttering. She obtained her PhD at the Australian Stuttering Research Centre (ASRC), Sydney, in 2007, where she investigated the manifestation and treatment of bilinguals who stutter in Singapore. She has successfully treated many children and adults who stutter, and is a Lidcombe Program Consortium Member. Her research interests include bilingualism, stuttering, and aphasia, and she has publications and research grants in various areas. She continues to teach and supervise students and speech therapists across different clinical and professional domains. Valerie currently works in private practice, and is a Senior Principal Speech Therapist at Changi General Hospital.


Junwei graduated from Flinders University, Australia with a Bachelor of Speech Pathology in 2011. She has since gained experience working with both children and adults with developmental and acquired communication and swallowing disorders. Her research includes stuttering, dysphagia and speech rehabilitation. Junwei is currently working as a Senior Speech Therapist with the Child Development Unit of the National University Hospital.