The greatest writers are those with the wildest vocabulary because they are better be able to choose the most appropriate word for what they want to say. So to be a good writer of English, you will need a broad, wide and deep vocabulary.
The English language has over half a million words so there is no end of learning, but if you only learnt one new word every day, you would know over 1,400 more words than you do now before the end of form 5. That probably is not going to be enough, so perhaps you should aim for a few more than that.
You may keep a vocabulary book to record all the new words you learn. Set yourself a realistic target to reach before the end - of - year examinations. 300 would be realistic for many, but some of you might think 200 more manageable. Those who think they are really clever might think 200 more manageable. Those who think they are really clever might target 500 or more - atleast 10 a week. Make sure it is a target that you will achieve. If you target for 1000 words and do not get there, you will only depress yourself. Far better to aim for 300 and find at the end of the year that you have reached 350!!
By the way, most malaysians are not interested in improving their vocabulary and tend to use the same words repetitively in both writing and speaking.....many think that their ability to converse in simple English is already more than anything but many do not think including phrases and idioms in their conversation and writing will create a good impression to anyone who are connected to them in any ways, but remember that this phrases and idioms are also need to be learnt. So do not forget these useful expressions.
Learning vocabulary for writing is not the same as learning vocabulary for examinations. For objective examination purposes you only need to recognise the word and know its meaning - it is called passive vocabulary. What you need for writing is words that you think of to apply in a certain situation. - your active vocabulary.
That is why you always need to learn how to use new words as well as the meaning. The meaning alone will do well enough for your passive vocabulary, but when you want to use for writing ( your active vocabulary), you will also need to know how to use them. It is a good idea to put all your words into new sentences as soon as you meet them. Use them - or lose them!!