Формальное согласие, как правило, такими фразами:
I completely (absolutely, totally) agree with you
I couldn't agree more
Exactly., absolutely.
There is nothing more to add to this
This is perfectly True.
Эти фразы используются, если вы абсолютно согласны, и вам больше нечего добавить, однако, в случае, если вы хотите добавить еще что-то, то можно сказать:
Well, I agree with you on the whole, but .
I agree in principle with you that.; however.
I can agree with you to a certain extent but .
You definitely have the point here but I'd like to add that .
I take your point, however it seems to me that .
It is certainly reasonable, however .
Если же беседа носит неформальный характер, то свое согласие можно выразить следующими фразами:
I'm with you on this point
I couldn't agree more
Yes, absolutely (of course)
Sure
There's no doubt about it
You bet!
I think so too
Несогласие в формальном языке, как правило, носит нейтральный характер, чтобы не обидеть собеседника и не привести беседу к конфликту:
Do you really think so?
I can't say I share your view on this.
I feel I must disagree.
I respect your opinion of course, but on the other hand.
I wouldn't say that, really.
Well, taking your point into consideration, I therefore must admit that .
Taking your point I still can't help feeling that.
I'm afraid, I disagree with you .
I'm afraid I don't see it this way .
To tell you the truth I have a different opinion.
В неформальном общении присутствует большая эмоциональность, поэтому, если вы абсолютно не согласны с утверждением своих друзей вы можете сказать:
Rubbish! Nonsense!
You can't be serious! You must be joking (kidding)!
No, no, it's not right.
I disagree with you completely.
Come off it!
Для более мягкого несогласия используются фразы:
I'm not sure you're right
I'm not sure about that ..
I agree up to a point but .
You could be right but .
But I thought .
Yes, but .
That's not how I see it ..
That's another pair of shoes.