It's a struggle to learn a second language at any age. Now, in a new study, scientist have found out the exact age after which your chances of reaching fluency in a second language seem to plummet: 10.
The study published in the journal Cognition, found that it's "nearly impossible" for language learners to reach native-level fluency if they start learning a second language after age 10. "It turns out you're still learning fast," says study co-author Joshua Hartshorne. "It's just that you run out of time, because your ability to learn starts dropping at around 17 or 18 years old," People who start a few years after age 10 may still become quite good at a language, the authors say, but they are unlikely to become fluent.
Kids may be better than adults at learning new languages for sound reasons. Children's brains are more plastic than those of adults, meaning they're better able to adapt and respond to new information. Kids may also be more willing to try new things than adults are. Their comparatively new understanding of their native language may also be advantageous.
These findings may seem discouraging, but it was inspiring for scientists to learn that the key period for fluent language learning might be longer than previously thought. Some scientists believed that the window begins to close shortly after birth, while others made it longer to very early childhood. Compared with those judgments, age 17 or 18—when language learning ability starts to drop off—seems relatively old.
For this study, the researchers created an online test promising to guess people's native language and home country based on their responses to English grammar questions. Almost 670,000 people took it, giving the researchers huge amounts of data from English speakers of many ages and backgrounds. Examining the responses and grammar mistakes allowed them to made unusually exact judgments about language learning.
