Phrases Making Plans and Invitations

I'm afraid I'm tied up then.

C1

Meaning

I'm busy at that time.

Example sentences

John: 'Can you make it to the meeting on Friday?'

Alice: 'I'm afraid I'm tied up then. How about Monday?'

John: 'I'm afraid I'm tied up then; I have a prior engagement.'

Alice: 'Would you be free for lunch tomorrow?'