I agree with what he said.
我同意他的建议。 I see eye to eye with my wife. 我和我妻子意见一致。 Sure, that would be fine with me. 当然，我对此没有意见。 Everything you have said is fine by me. 你所说的我都同意。 I quite/totally/absolutely agree. 我完全赞成。 I agree although I still have some reservations. 我基本上同意，但我仍有所保留。 I don’t see anything wrong in his proposal. 我认为他的建议没有什么不当。 Doesn’t sound bad. 听起来还行。 Nonsense! How can you say that and keep a straight face? 胡说八道！你怎么能不动声色说那些话。 No, you’re way out of line this time. 不行，这一次你做得不合规矩。 No way./ Not a bit. 根本不行。 No, I could never agree to sign this contract. 不，我无论如何也不会签这份合同。 I quite agree with you. 我很同意你。