When we offer something to somebody we can use the following forms:
Would you like some coffee?
Do you want some fruit?
Can I get you something to drink?
What would you like for desert?
We can accept an offer in the following ways:
Yes please, that would be great.
That's very kind of you. Thank you.
We can decline an offer using an expression like those below:
No thanks, I'm fine.
I'm full to be honest. Thanks anyway.