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Hello zozo,
Since you are at an intemediate level you need to apply some methods to improve such as :
Reading at your own level of comprehension and alway looking for new words in dictionary .
Repeating and learning the new words so that you don't forget them easily
Listen to english lyrics in songs and watching movies in english language .
Doing any entertaining activity you like using the english language such as games etc .
Exercising grammar to be able to built correct sentences through grammar books or lessons online .
Practicing with native english speakers so that you get hold of the correct accent and learn new expressions used natively .( if you don't have this opportunity than practice at least with good english speakers ).
Use online chat programs such as itlaki to practice and voice chat with natives preferrably .
All that will help you increase your vocabulary , enchance your pronunciation and improve gradually , good luck :)