你好
我认为你不对-----I think you are wrong 或 I don't think you are right或 I think you are false.
这些都有这个意思
希望帮到你
I think you are wrong.
I don't think you are right,这样说显得对人家不尊重,我感觉这样说会比较好
i dont agree with you.我不赞同你的意见
I dont think you are right! I hold that you are wrong!
i think it 's your fault !