When it comes to learning a language, I think the best age to do so would be around 6 to 12 years old. I’d say at average 6 years old is when you can make sentences and have an overall understanding of words.
I think the last year when it’s convenient to learn a language, is at 12, because after that age you keep your accents from your native tongue, and because it’s generally the beginning of the last years when learning is easy.
By the way, when it comes to learning languages (of course, in this case, English), I’m actually at the native stage. That of course, is to be expected though, considering I originate from the States.
Learning any language is like learning any task, it takes practice. The thing that makes learning languages a bit more difficult, however, is the fact that you have to learn 5 things at the same time (like writing, reading, speaking, etc.)
However, just remember to be patient and to take things one step at a time.
-Sebastian Mothelet :)