1. Try reading simple English books or even storybooks.
-That could really help you a lot. Just like in my case, I used those simple and the most basic books in English then followed by the medium level English and the hardest.
2. Have Determination.
-Don't give up nor be lazy in learning those hard and complicated terms. If you really want to learn then don't just sit around and wait for a miracle. Work hard.
3. Read poems, fables, etc.
By reading also these kinds of English books, you'll be able to know how to rhyme English words and would boost your vocabulary too.
Hope I help! :)