English help, please come(easy).?

It's not bad at all; you could easily get away with it. However, there are a few small flaws, and it is mixing a formal style and an informal, slang style. The conversation would more likely go one of these ways. I've capitalised word changes, but look out for punctuation changes (mostly ! and ---, where --- represents an em-dash). Note that I don't know Chinese (wish I did), so I'm just checking the English.

Formal:

Ben: The 2010 World Cup has already started!
Sally: Do you know where it will TAKE place?
Ben: Yes, I heard THAT South Africa is hosting it this year.
Sally: Do you know that this is the first world cup EVER HOSTED in Africa?
Ben: Really? THAT is great! I am going to WATCH the games on TV!

Sally: Look --- they are playing soccer!
Ben: Let’s go to the soccer field and watch them play.
Sally: I don’t know anything about soccer.

Informal:

Ben: The 2010 World Cup has already started!
Sally: Do you know where it takes place?
Ben: YEAH, I heard South Africa is hosting it this year.
Sally: Do you know that this is Africa's first world cup?
Ben: Really? THAT'S great! I am going to see the games on TV!

Sally: Look --- they are playing soccer!
Ben: Let’s GO WATCH.
Sally: I don’t know anything about soccer.

Sally: Do you know where it's taking place?
Sally: Did you know that this is the first world cup in Africa?
Ben: Really? This is great! ( I think a exclamation point goes here since he's excited) I am going to watch the games on TV!

Everything else I believe is fine, this is just my personal opinion though.