All there's left to do is run.that is all there is to it.这两句

All there's left to do is run.that is all there is to it.这两句什么结构,
这两句为什么要这样写法?能否给我详细分析下?另外再问下What I mean is that we feel is the same这句是什么结构feel is这两个不都是动词,没见过这样的用法,也帮忙分晰下.thank you very much