1. I'm sorry to interrupt your conversation, but I've got something urgent to tell you.
2. Sorry to butt in.
3. I'm sorry to barge in like this, but I need your help with a problem.
4. Wait, can I put in a word here?
5. Can I say something?
6. She kept cutting in when I was making my point.
7. He chipped in when I was about to answer his question.
8. He always breaks in on our discussions.
9. My boss got really mad when his secretary chimed in during the meeting.
10. It's very impolite to interpose in such a formal seminar.