Ages: 12-36 months

Parents ask all the time about how they can best raise a child to be proficient in two languages. This is a complicated topic, and we recommend reading an article we published in 2013.

In recent years, we’ve been trying to understand how bilingual children process a mix of two languages, as in, “Where’s the perro?” or “Dónde está el doggy?” These kinds of sentences are fairly common in bilingual households. Children in these studies looked at pictures of common objects or animals and heard simple sentences asking them to look at one of the pictures. For some kinds of language mixing (like when the switch happens at a noun), there can be a very slight delay in identifying the right picture, but for other kinds of language mixing (like when the switch happens on an adjective), there’s often no delay. Our broad takeaway from this research is that bilingual families can use their two languages naturally, and children will adapt to their language environment, showing efficient language processing and typical word learning.

In other research, we investigated how parents can best help their child learn words in two languages. We noted that parents (and picture books) sometimes offer immediate translations of certain words (like saying perro and doggy back to back), and sometimes use their languages at separate times entirely (for example, they might talk about a dog in Spanish for a while, and then switch to English after a few minutes).

We found that bilingual children were good at learning new words regardless of whether translations were spoken immediately or later on. Our results show that different patterns of bilingual interactions provide equal learning opportunities for bilingual children’s vocabulary development.

Researchers: Jessica E. Kosie, Rachel Tsui, Laia Fibra, and Krista Byers-Heinlein