Language Magazine – Staff Writer 
After years of research suggesting that the “critical period” to learn ends before the age of 10, an enormous new study of well over half a million learners suggests that children remain very skilled at learning the grammar of a new language much longer than expected—up to the age of 17 or 18. However, the study also found that it is very difficult for people to achieve proficiency similar to that of a native speaker unless they start learning a language by the age of 10. (more)