Practice the language is very useful to not to forget it.

for me... the best way is to watch movies whitout subtitles, and of course read a lot

You want to improve speaking english ? Improving english language or any requires some practice and dedication ,some of the ways most efficient are : -Reading: You can read in books , online or any other method at your level of language at the moment trying to gradually read more dificult readings looking up always new words . - Using music and films as a way to learn: You can listen to english music ,watch movies , online entertainment in english , you will find some much material video and audio in english language that will help you increase your vocabulary and inhance your speech . - Speaking: If you have the chance to conversate with natives and listen to their accent ,that is a great way and quick way to learn , if not natives than at least people who speak as good as you or better . Good luck:)