The speed at which English-speaking bilingual toddlers learn vocabulary in their other language is determined by its linguistic distance from English, researchers have shown for the first time.
‘Findings show that children’s production of additional language words was improved when this language was phonologically close to English – such as Dutch, Welsh, German – as compared to more distant languages – such as Cantonese, Polish and Greek,’ their study concludes.
The findings could have major implications for the assessment of language development in bilingual children (see story below).
The team, led by Caroline Floccia of Plymouth University, measured vocabulary in 372 two year-olds over a two-year period.
All the subjects lived in the UK and were learning British English plus another of the thirteen most commonly spoken second languages in Britain.
To measure the distance between English and each of the other languages they used ‘cognate distance’.
This is the most common measurement of language distance and refers to translation equivalents sharing common historical origins – for instance lait in French and leche in Spanish.
They also ranked language pairs by taking into account word order and morphological complexity. Cantonese, for instance, is morphologically closer to English than French, which has a higher ratio of morphemes to words. Spanish has a similar verb–object word order to English, while Hindi does not.
Children acquired a phrase more readily in their other language if it used the same word order as British English and was phonologically close to it.
Vocabulary acquisition was measured by Communicative Developmental Inventories, which are parental reports of their child’s vocabulary against a checklist of familiar words.
Against a set of 100 English words, toddlers understood on average 67.9 English words and produced 41.2, according to their parents. Presented with the vocabulary in their other language, they understood 54.9 per cent of words and produced 24.2 per cent.
The closer the languages, the more vocabulary the toddlers picked up. Those whose other language was Dutch understood 76.9 words and produced 45 terms. Participants with Hindi as an additional language acquired 61.6 words and produced 32.6 terms.
Research helps target bilinguals with language difficulties
The first assessment kit aimed at identifying bilingual children with speech development problems has been developed by a British team of researchers.
The kit is based on research (see above) with speakers of the thirteen most commonly spoken second languages in Britain, but has been shown to work with toddlers from other language groups.
The UK Bilingual Toddlers Assessment Tool (UKBTAT), as the kit is known, includes a list of familiar English words that parents tick off when their child recognises or can say them, and a similar list of common terms in the child’s other language. Language difference was found to be the main factor affecting vocabulary acquisition.
A Language Exposure Questionnaire is also used to assess the proportion of time the child spends engaged in each of their two languages. The research found no significant difference between children whose parents spoke English as a second language and those who had one native-speaker parent. Neither the number of native English speakers in contact with the child nor the number of L2 speakers had a significant impact on the language levels the parents reported. More predictably, the study found girls outperformed boys and mothers engaged in conversation with their children more than fathers. This is believed to be the first study that collected data from a large cohort of bilingual toddlers learning a variety of language pairs, ‘to capture the effect of language community and linguistic distance on other factors known to modulate vocabulary growth in bilingual children.’
While the norms of vocabulary growth highlighted by researchers are specific to children learning British English as one of their languages, the same methods can be applied to any sample of English-speaking bilingual toddlers.
Researchers successfully extended the study to a further 58 bilingual toddlers learning British English and a new additional language not included in the original target set. It is hoped the UKBTAT will enable professionals, including language therapists, social workers and educational psychologists, to identify bilingual toddlers with language processing difficulties and lead to better interventions to support them.
Previous assessment methods have been based on monolingual children and have taken no account of the differences typically found in bilingual children.