The legal obligation to provide language services has prompted considerable interest from policymakers who want to know: how long does it take for DLLs to learn English? There is not, however, a clear-cut answer: the length of time depends on a range of factors. Specifically, the variables influencing the trajectory of DLLs’ English development fall into two categories: individual factors and school factors.
There is substantial diversity within the DLL population, and thus many elements must be taken into consideration with regard to the time it takes DLLs to acquire English. The most important of these factors include age, exposure to English, and prior education.
First, one theory of language acquisition suggests that humans have a critical or sensitive period within which to learn language. This is generally thought to be before age nine, when brain development is particularly flexible. It should be noted that this theory is largely based upon research of first rather than second (or third, fourth, fifth, etc.) language acquisition and that there have been many language learners who acquire another language later in life. Still, a body of research shows that language acquisition tends to be quicker in children than adults.
The second individual factor (related to age), is amount of exposure to English. Time spent living in an English-speaking environment is usually correlated with a higher level of English (although the total English immersion, or “swim or sink” model of language learning is highly ineffective).
While the majority of DLLs are born in the U.S., their exposure to English may vary according to the language communities where they grow up. For instance, many DLLs also experience frequent migration either within the U.S. or between the U.S. and their home country. The resulting interruptions in schooling can have negative impacts on their language learning and educational growth.
Third, DLLs’ prior education—in any language—plays an important role in their English acquisition, as more education is typically associated with a deeper understanding of language and academic content, both of which support English acquisition.
First, the type of instructional program into which DLLs enter can impact the time it takes to learn English. Generally, bilingual education programs—those that allow DLLs to learn in their first language while simultaneously acquiring English—have proven to be extremely successful. One study comparing children’s outcomes from several language-learning models found that DLLs in English-Spanish bilingual programs outperformed DLLs in English as a Second Language (ESL) or mainstream English programs on both literacy and math tests by fifth grade. These findings do not speak to the time it took children to learn English in each setting, but they suggest that more time in a bilingual program may support English achievement.
Second, the presence of bilingual and bicultural staff members may also facilitate children’s English acquisition, particularly in settings where formal bilingual education is not an option. Anecdotal and qualitative research suggest that teachers who are familiar with their students’ languages and cultures may readily draw upon them in instruction. Lastly, there is substantial evidence that DLL family engagement supports positive educational outcomes. In particular, family literacy initiatives have been shown to facilitate DLLs’ emergent literacy and oral language skills in English.
Length of Time to Language Acquisition
Even though these various factors make it hard to know exactly how long it takes DLLs to learn English, researchers have developed a range. They estimate that it can take up to three to five years to achieve oral proficiency—the type of language children need to engage in everyday interactions—and four to seven years to be at the same academic level as their native English speaking peers, which includes reading and writing across subject areas.