Begin和start后doing和to do的区别?

问题描述:

Begin和start后doing和to do的区别?
谁能明确的说一下区别?以前看过好多解释,但做题时就觉得都模棱两可.老师说to do是以前没做过要开始去做,但课本上有一句话:It'll start raining.到底要怎么区分呢?

begin to do, start doing 用的多一些