I don't agree. 我反对。 I can't agree. 我不能同意。 I doubt it. 我怀疑。 Objection! 我反对。 That's not what you said. 你不是这么说的。 I can't buy that! 我无法相信。 Bad idea. 馊主意。 No good. 那可不好哦! Let's not. 算了吧! That's impossible. 那怎么可能。 That's absolute nonsense. 那完全是胡说八道。 It won't work. 行不通。 Not always. 不总是这样。 Not really. 不是那样。