It's very kind of you _____(say) so.并说明理由,

问题描述:

It's very kind of you _____(say) so.并说明理由,

这里可以填两个答案,to say或者saying。
It's very kind of you to say so.表示将要说的。
It's very kind of you saying so.表示已经说过的。
另外对于后者,It's very kind of you (by /for)saying so.直译的话就是:通过(因为)你这么说,我觉得你很好,所以是省略了介词,应该用saying.

It's very kind of you to say so.
动词不定式to say so 是句子的主语,动词不定式作主语常用it 来代替。
满意请采纳,希望对你有帮助

It's very kind of you to say so.
be kind of somebody 后要接to do something.这是一种固定用法.
例句:
It's verykindof you to help me.
谢谢您好心帮助我.
It's very kind of you to tell me.
你来告诉我真的太好了.
It's very kind of you to help me with these problems.
你帮我解决了这么多难题,真是太好了.