Question

I hope so.和That's a good idea.是什么意思？

Answer 1

I hope so.：我希望如此；我希望这样；但愿如此
例句：
1.I hope so , I'm as one of the fans that I hope that's the case as well.
我希望是，我也是粉丝我希望情况是那样的。

2.KELLY: Oh, I hope so! I would love to be in a movie with him.
凯莉：希望如此。我想和他一起拍电影。

3.I hope so. I enjoyed playing tennis with you. See you next week.
希望我能打好。和你一起打网球很愉快。下周见。

That's a good idea.：好主意；那是个好主意；这是个好主意
例句：
1.That's a good idea. All right, I'll withdraw and get down to it if you don't mind.
这个主意不错，好吧，如果你不介意，我要回去着手办了。

2.I'm not sure that's such a good idea.
我可不认为这是个好主意

3.Molly : That's a good idea. Let me think about it.
莫莉：这是个好主意，让我考虑考虑。

Answer 2

我也希望是这样。
那是个好主意。