learning english

how many much time should I spend studying to learn english very well?!! It is not easy =/

I agree it isn't easy to learn English or any foreign language. I think the key is to do it EVERY DAY. I would dedicate at least 15 minutes a day to formally study English. And that is just a minimum.

One thing that helps is to immerse yourself in the language. You can listen to audio podcasts in English, watch movies in English (with subtitles), study in a formal class, do notebook entries here in Italki, etc.

Another thing that is important to remember is to be patient, and not be afraid to make mistakes! 

There is a saying that goes: You can't eat an elephant in just one day!

Learning English

How much time should I spend studying to learn English very well?!! It is not easy =/

In my view, it is more important to be consistent in your studies than to make your study sessions longer.  As little as 15 minutes every day can have an impact on all areas of your language study.  Some people find that social pressure - for instance, through language lessons or exchanges - can help them stay motivated.  Think of it like exercise - would it be better to jog for 30 minutes every day or to jog for 2 hours once a week?