The following phrases can be used to compliment people on their personal qualities or abilities:
You are… – with strong stress on are and the following adjective or noun.
You are so… You are such a… How… you are! I wish I had your…
On possessions:
You’ve got a nice/lovely/beautiful/wonderful… What a nice/lovely/beautiful/wonderful… you’ve got! I wish I’d got a… like yours.
On clothes and appearance:
That’s a nice/lovely/beautiful/wonderful… (you are wearing) What a nice/lovely/beautiful/wonderful… (you are wearing) You do look nice/smart in/with that… I (do) like your… do (stressed) makes the statement more emphatic.
On achievements: The form used here usually depends on the type of achievement. However, the general verbs be and do can be used in various situations:
You were wonderful/superb/magnificent! You were great! – More colloquial
You did very well!
What a nice (-looking)/convenient/delicious… You’ve done a wonderful job. You’ve done wonders with the…
A compliment can be introduced by I must say.
If you consider the compliment to be deserved you can simply say Thank you, but this may sound self-satisfied or immodest. Here are some modest responses:
To compliment on personal qualities and abilities:
Do you really think so?(Oh) I wouldn’t say that. (Oh) I don’t think I’m (any) better/ more… than anybody else.(Oh) I don’t think I’m better… than you/ anybody else. You’re… too (yourself).
On possessions, clothes:
Do you like it (them)? I’m glad you like it. Yes, I’m quite/ rather pleased with it (myself). It’s not bad, is it? – usually an understatement, used out of modesty (real or assumed)
On achievements: Here either ‘echo’ question or one of the responses given above can be used, depending on the situation and the form of the compliment.