My problem is I know the grammer but when i want to speak and use them I can't concentrate and get confused.
i can't change verbs to correct form and time.

I can't match third person singular with verbs and conjunctions

and so on... with other rules.

when it comes to speacking I get stressfull and.....

To mitra:

Certainly, grammar is important to make your speaking and writing more decent and understandable, but remember even you have been familar with all details in English grammar, it cannot ensure you to speak and write very well unless sufficient practice and trial.

Firstly, I would advise you not to be streesful as you are not supposed to be a native speaker so unnecessarily to speak as fluently as a native speaker. There are a couple of rules you have to follow while you are speaking and writing for sure, yet just relax and do your best to speak out naturally with your knowledge acquired in the class. That is all, no worries, no tension, no embarrassment, no adverse emotion.

hi, i have some problem.. In a question, when i use "are you?" Or "do you"?