1. To be aware of
I wasn't even aware that he was ill.
2. To realize
I realize how difficult it's going to be, but we must try.
3. To recognize
He sadly recognized (that) he would die childless.
4. To appreciate
I appreciate that it's a difficult decision for you to make.
5. To acknowledge
We acknowledged the need for reform.
6. To notice
I notice you aren't quite convinced.
7. I see
"I'm tired." "So I see - you've been yawning all afternoon."
8. I see what you mean.
9. fair enough
I'm just annoyed with him because he's behaved so badly." "Fair enough."
10. All right./OK.
11. I see/take your point.
12. I don't blame sb
I don't blame him for getting angry - she's being really annoying.
13. I get what you mean./I get you.
I told that joke to Sophia, but she didn't get it.