Don't look happy. help me please

They are both fine. They can be used in articles.

Hello, Both of these sentences make sense but it is better to say "You look unhappy"

Well, they mean slightly different things. If someone had a very neutral look, neither happy nor unhappy, they you could say, "You don't look happy" but you wouldn't say "you look unhappy."

Thank you for these information.



But I mean these as below.

You don’t look old = You look not old. Are Both same in expression?

You don’t look happy. = You look not happy. Are Both same in expression?

You don’t look more than 20 years old. = You look not more than 20 years old.

Are Both same in expression?

You don't look old = You look not old. Are Both same in expression?-- The second is no good.

You don't look happy. = You look not happy. Are Both same in expression?-- The second is no good.
You don't look more than 20 years old. = You look not more than 20 years old. Are Both same in expression?--Yes.
It's said that "You don't look ...." mo

Hello Mister Micawber



More than You look not

But now after your explanations, it doesn't seem that each is workable.



Thanks again.

No, not workable nowadays. Perhaps 200 years ago.

I got it! Thank you very much.