1.get sb to do / doing这里sb 和 to do /doing 之间存在逻辑主谓关系,to do 表示还没做的事,而doing表示正在发生的动作 .get sth done sth 和done 之间存在逻辑动宾关系.done表示完成的动作.
2.It is clever of you to work out the problem.( You are clever to work out the problem用Of强调人)
It is important for us to learn English ,( To learn English is important .用for 强调动词不定式的动作)
3,看看语法书,或找老师补一补其实很简单的,自己平时多理解总结就好了.