Li Sheng & Pumpki Lei Su
University of Delaware
Based on research from the USA and UK, about 7% of the population have Developmental Language Disorder. By extrapolation, that would mean there are five million four-to-nine-year-olds with DLD in China. Unfortunately, DLD is largely unknown and undiagnosed in China because there are few diagnostic tools and few speech-language pathologists.
Many signs of DLD in Mandarin-speaking children are similar to those in other languages. These include beginning to talk at a later age, difficulty understanding long sentences, problems with finding words, and poor story telling skills. In an ongoing review of published studies on Chinese DLD (including Mandarin and Cantonese), we gathered 41 articles that compared children with DLD to typically developing children of the same age. Table 1 below shows that across multiple studies, the average difference between the two groups is large (>.8) on four out of five language measures.
|Table 1. Average effect size across studies|
|Language Measure||Effect Size||What does this mean?|
|Narrative macrostructure||1.28||Stories are missing key plot elements|
|Mean length of utterance||1.31||Utterances are shorter|
|Number of different words||1.11||Use fewer diverse vocabulary when speaking|
|Number of total words||0.79||Say fewer words when talking or telling stories|
|Non word repetition||1.18||Remember fewer sounds they just heard|
In addition to these generic signs, children who speak Mandarin show weaknesses in the following areas that are specific to their language.
- Omitting the verb particles that tell the listener whether an action is ongoing or completed. For example, saying “宝宝吃饭 baobao chifan [baby eat meal]“ instead of “宝宝吃过饭了 baobao chi guo fan le [baby has eaten meal]”, saying “爷爷看电视yeye kan dianshi [grandpa watch TV]” instead of “爷爷在看电视yeye zai kan dianshi [grandpa is watching TV]”
- Overusing the generic classifier “个 ge” and misusing specific classifiers. For example, saying “一个山yi ge shan [one ge mountain]” for “一座山yi zuo shan [one zuo mountain]”, “yi ge shu [one ge tree]” for “yi ke shu [one ke tree], or “一只男孩yi zhi nanhai [one zhi boy]” for “一个男孩 yi ge nanhai [one ge boy]”
- Difficulty producing complex sentences such as bei passive sentences. For example, saying “它被缠着那棵树 ta bei chan zhe na ke shu [it was by that tree wrapped around]“ “它被那棵树缠着 ta bei na ke shu chan zhe [it was wrapped around by that tree]“
These errors or omissions are also seen in typically developing Mandarin-speaking children, but they are much more frequent in the spoken language of children with DLD. Interestingly, tone production is remarkably accurate in typically developing children as young as two years old. So far there is no evidence to suggest that tone production is a weakness for children with DLD.
The study of Mandarin DLD is still a young field. As the disorder attracts more attention, our knowledge will evolve. In addition to understanding the symptoms of DLD in Mandarin, we need to develop both assessment tools and treatment programs to serve this enormous population.
- Hao, Y., Sheng, L., Zhang, Y., Jiang, F., de Villiers, J., Lee, W., & Liu, X. (2018). A narrative evaluation of Mandarin-speaking children with language impairment. Journal of Speech, Language, and Hearing Research, 61, 345-359.
- Li, X., & To, C.K.S. (2017). A review of phonological development of Mandarin-speaking children. American Journal of Speech-Language Pathology, 26, 1262–1278.
- Sheng, L., Shi, H., Wang, D., Hao, Y., & Zheng, L. (2020). Narrative production in Mandarin-speaking children: Effects of language ability and elicitation method. Journal of Speech, Language, and Hearing Research, 63, 774-792.
- Sheng, L., Su, P.L., Wang, D., Yu, J., Lu, T.-H., Shen, L., Hao, Y., & Lam, B.P.W. (in preparation). Manifestations of developmental language disorder in Chinese children: A systematic review and meta-analysis.