Do you understand？
Is that clear？
Get the picture？ =Did you grasp the overall situation？
Do you know what I mean？=You know what I mean？=Are you following me？=Do you get my drift？
Are you listening to me？ =Are you paying attention？
Are you blind？ =Can‘t you see？=What’s the matter with you？
You know what I‘m talking about. =You know what I mean.=Don’t play stupid.
I said that， didn‘t I？ =Did I repeat myself？
Do you know that？=Do you know about that？
Do you happen to know.。.？
I can’t tell the difference.
Can you hear me？
Did you hear me？
I understand. =I get it.
See？ =Do you see？=Do you understand？=Do you get it？
I understand very well.
I think I understand.
I see what you mean.
I know that too well.
I see your point.=I see what you mean.=I understand what you mean.=That makes sense.=I get the point.
I get it.
I got it. =I see.
I know that much！
That solves it.
All right， all right. I understand.
I know. =I know that.=I know it.
I know that person.=I‘m acquainted with that person.
I know him by sight.
Yeah， I heard about it.=Yeah， someone told me.=Yes， I’ve been told.=Yeah， I know.
I hear you. =Yes， I understand.
I‘m following you. =I’m with you.=I‘m following.
Makes sense. =That makes sense.=Makes sense to me.=You’re making sense.
I don‘t understand.=I’m not following.=I don‘t get it. =I’m confused.
I don‘t really understand.=I don’t understand very well.
That‘s not clear.
I can’t see your point.
I can‘t understand what you mean.=I can’t see what you mean.=I don‘t understand what you’re trying to say.=I don‘t get your drift.
I’m not sure what you mean.=I‘m not sure I understand.=I’m not sure I see what you mean.=I don‘t know if I understand what you’re trying to say.
I don‘t know what’s what. =I don‘t have any idea what’s going on.=I don‘t know anything any more.
It’s over my head. =It‘s beyond me.
Your guess is as good as mine.
The more I think about it， the less I understand it.
I don’t know what he is driving at. =I don‘t know what he intends.=I don’t know what he is getting at.=I don‘t know what he is trying to do.=It’s not clear. =That‘s unclear.
What’s she after？=What‘s her game？
I have no idea.=I have no clue.=No idea.=It’s all Greek to me.
I didn‘t know that.=That’s news to me. =I wasn‘t aware of that.
I don’t know.=I have no idea.
I don‘t know for sure. =I don’t know for certain.=I‘m not absolutely sure.
No one knows for sure.
How should I know？
Who knows？ =Nobody knows.=No way of knowing.=There’s no way of knowing.=It‘s impossible to find out.