I agree. 我赞成。
I agree with you on this point. 在这一点上,我同意你的意见。
What a good idea! 真是个好主意啊!
I can't object to it. 我不反对。
I can't agree. 我不同意。
No. 不。
You've got that wrong. 你弄错了。
Bad idea. 歪点子。