have……do：have sb do sth让某人做某事
I will have him cut my hair.
have……done：have sth done让某事被做；还有个意思是表示主语的坏遭遇；
其实这个结构是由have sb do sth变过来的：have sth done by sb.
I will have my hair cut by him.
I had my leg broken.
have……doing：have sb/sth doing让某人/某物一直做……
Don't have the horse running all the way.
以上三个结构have表示“让……”,是个使役动词
have……to do有……要做
I have a lot of work to do.