It's all my fault — . Sorry, it's my fault — , ( , ).
I'm sorry, I did it — , .
I'm sorry, I said it — , .
I'm sorry, I wrote it — , .
I'm sorry, I didn't do it — , .
I should have done it — .
I shouldn't have done it — .
I'm so sorry ( ) I beg your pardon ( ) I'm sorry, I can't (, ) I'm glad to see you ( ) It's very kind of you ( ) It does you credit ( )
Thank you anyway ( )
Not at all ( )
Thank you in advance ( )
Don't mention it ( )
May I help you? ( )
You are welcome ( )
No problem/ that's ok/son't worry about it ( , )
This way, please (, )
I'm sorry, I didn't catch you (, )
After you ( )