i hope so的否定形式不能用i don't hope so.还有没别的动词也是这样的

. ---- Is he coming back tonight?
---- I think so.
---- Is he feeling better today?
---- I’m afraid not.
这种用法常见的有：How so? Why so? Is that so?
I hope so. He said so 及I suppose not. I believed not.
I imagine not. I expect not. I hope not. I guess not等。
（但I don’t think so比I think not更常用）。

能，i think so .i do not think so

wish