1. I'm sorry, but I can't.
2. I'm sorry I can't.
3. Sorry, but I can't.
4. Sorry I can't.
5. I'm sorry that I can't.
Can we use all the expressions?
6. I'm afraid, but I can't.
7. I'm afraid I can't.
8. Afraid, but I can't.
9. Afraid I can't.
10. I'm afraid that I can't.
[What about these ones? 'Afraid' is used instead of 'sorry.'
Which ones are acceptable?]
1. I'm sorry but I can't come out and play.
This is a complete sentence : )
As complete sentences they make sense.
So #1 - 7 are ok when put into complete sentences.
#8 , #9 and #10 work as well in the sense that you are afraid you have to break your appointment.
I'm afraid I can't make our date.