Just find harder more describtive vocabulary. Read more books, get a tutor, read newspaper, watch the news. You have to build your english up not just one day or two could make it good.
You must read some stories which are written with simple english, and always use dictionary to check the meaning as you found some words which are you don't understand. Then, take some english course, i.e. 英國文化協會, make some practise for oral, speaking english is most important. Please step by step do it if you want to upgrade the knowledge of english.
You should read more english books and newspaper..........i think if you really want to improve your english, you can read newspaper every day. Also, you can watched the news in the TV.....