冯丽, I would strongly advise you not to use slang expressions unless you are absolutely sure that the person you are chatting to would also use those same expressions in the same situation. You may confuse or offend someone by using a slang expression inappropriately. Many slang expressions are specific to a certain country or region, or a particular age or social group. I would be very careful about using them. If you want your internet friends to like you, just be yourself. Be honest. Relax. Say how you feel. Let your natural personality show. Your friends will soon find out what the real 'you' is like.

I think you are looking for some idiomatic slang words in English. For example: I'm knackered = I am very tired I'm just chilling out = I am relaxing Brr! I'm freezing! = I am very cold Give me a break = please be more understanding Whassup? = What's the matter OR What is happening in your life? How ya doin'? = How are things with you? Get a life, you saddo = Go away and stop annoying me You crack me up = I think the things you say are very funny