If you want to improve your English, you may already know my standard responses:
1) Watch popular movies/TV shows in English with the ENGLISH sub-titles turned on.
2) Listen to music in English, with the lyrics in front of you, and listen to it and sing along until you can do it fluidly.
3) Read books, magazines, articles--anything!--in English, making sure to look up any new words.
4) Talk to yourself aloud in English…and think through phrases and conversations in English
...And then, take time to look at and work through the following web-sites:
My suggestion is to pick ONE of these web-sites and go through all that it offers--the instruction, the quizzes, everything! Then, move on to another of the web-sites. After that one, do the last.
Any combination of exposing yourself to English in various formats is going to improve your language skills. But, you have to REALLY want it. "You can get it if you really want it," says one popular song...and it's true! However, you have to REALLY want it...and if you REALLY want it, you'll do whatever is necessary to get it!