How to express agreement or disagreement

1. Agreeing or Disagreeing
Agreeing with an opinion
I agree with this opinion.
I completely agree with this view.
I agree with you entirely.
This is absolutely right / That’s true.
I couldn't / can't agree more.
You’re absolutely right
Of course.
Yes, I agree
I think so too. / I don’t think so either.
That’s a good point.
Exactly.
So do I / Neither do I.
I’d go along with that.
That’s just what I was thinking.
I couldn’t agree more.
Partial agreement:
I agree with this point of view, but... This idea is right, but...
I agree with you, but...
Disagreeing with an opinion:
I'm afraid. I can't agree with you.
I disagree with you.
I don't agree with you / at all.
I'm not sure I agree with you
I think you're wrong
I see your point but …
That’s different /
However,…
That's not entirely true.
On the contrary…
I'm sorry to disagree with you, but…
Yes, but don't you think…
That's not the same thing at all.
I'm afraid I have to disagree.
I'm not so sure about that.
I must take issue with you on that.
It's unjustifiable to say that...