used to introduce a word or phrase that contrasts with what was said before

I'd asked everybody but only two people came.

By the end of the day we were tired but happy.

used when you are saying sorry about something

I'm sorry but I can't stay any longer.

used to introduce a statement that shows that you are surprised or annoyed, or that you disagree

‘Here's the money I owe you.’ ‘But that's not right—it was only £10.’

I had no choice but to sign the contract.

used before repeating a word in order to emphasize it

Nothing, but nothing would make him change his mind.

used to emphasize that something is always true

She never passed her old home but she thought of the happy years she had spent there .

a reason that somebody gives for not doing something or not agreeing

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