BBC – Staff Writer
“If you want to have native-like knowledge of English grammar, for example, you should ideally start before age 10, say the researchers. People remain highly skilled learners until 17 or 18, when ability tails off. The findings, in the journal Cognition, come from an online grammar test taken by nearly 670,000 people of different ages and nationalities. The grammar quiz was posted on Facebook to get enough people to take part. Questions tested if participants could determine whether a sentence written in English, such as: “Yesterday John wanted to won the race,” was grammatically correct.” (more)