The worst error that a language learner could do is to believe to have a perfect knowledge of the language he is sudying, that there isn't much to improve anymore.
That's also the most common error we do, I reckon. I did so.
My high marks at school made me believe that my English was perfect since I had any problem talking with natives and writing short texts, but I had to change completely idea about myself when I had to take the FCE Cambridge exam.
I discoverd, all of a sudden, that there were still many things to improve - my pronunciation most of all, and that my level was not as high as I expected.
At first I felt very discouraged by it, but then I started working hard on it and I can swear my English improved a lot since then, both in terms of grammar than of speaking skills and pronunciation.
I'm still working hard on it, especially on grammar, and I'm dreaming to study English in an university in UK now.
European applicants are asked to take also an exam, in order to denmostrate their skills with English; this is another reason to study more!
I think English is a beautiful language, and that it is not as simple as most people believe; having a correct command of the language is a pretty difficult goal to reach!
What do you think about?
How good is my english in your opinion? :D