In-depth research review of Dual Language Learners: Highlights from a new report

Published on Saturday, June 08, 2013

“The video gave wings to my talking with my children.”

Mandarin-speaking mother after viewing Language is the Key video.

According to a new report from the University of North Carolina young English-language learners benefit most when BOTH the home language and the school language are supported. The report presents an extensive review of research about children who are learning two languages during a critical period of development, age birth to five.  The research findings are used to make recommendations on federal, state, and local policy.

The report addresses how best to prepare Dual Language Learners for literacy and learning in school.  (Dual Language Learners, DLL, are young children who are learning through two languages.) The number of children growing up with two languages entering school in the United States has grown by 40% in the last decade. By 2020, DLL preschool-age children will outnumber their monolingual English-speaking peers. Here are a few highlights from the extensive report:

  • The most important thing a high quality Early Childhood Education program can do is use the DLLs’ home language in addition to English. Since DLLs are learning through two languages, both languages need to be supported.
  • The child’s first-language skill and home literacy experience are strongly related to successful second language acquisition.
  • Differences in development between DLLs and their monolingual peers DO NOT equate to deficiencies.
  • While DLLs are developing two languages from birth to age 5, they may need additional time to reach proficiency in both languages. Problems with DLLs’ development arise when they are not provided sufficient language learning opportunities and support for both languages.
  • Exposure to and acquisition of two languages in the early years has limited, if any, detrimental effects. But it can have important positive effects in metalinguistic awareness, cognitive flexibility and executive function.

When you show Language is the Key videos to parents of young DLLs you give them important tools to support their children’s language development in the home language. Parents also express relief knowing they can use the language they know best to communicate with their children.  Many parents hesitate to use their home language with their children because they fear it will slow English acquisition. This new report suggests just the opposite. Parents support both the home language and English development when they use the home language with their children. In cases where there are no teachers who speak the child’s home language the role of the parents becomes even more important as they may offer the only support for the home language.

Preview Language is the Key videos on our website. They are available in English, Spanish, Mandarin, Vietnamese, Korean and Tagalog.


Castro, D. C., García, E. E., & Markos, A. M. (2013). Dual language learners: Research informing policy. Chapel Hill: The University of North Carolina, Frank Porter Graham Child Development Institute, Center for Early Care and Education—Dual Language Learners.

Read the full report from the Center for Early Care and Education Research-Dual Language Learners at the University of North Carolina, Raleigh. (CECER-DLL).

Read the Policy Brief from CECER-DLL.