get sb.to do= have sb.do人某人做某事
get sth.done= have sth.done使得某事被做
get sb doing sth.让某人开始...起来
have sb.doing让某人一直做某事
eg.I had Tom type the letter.= I got Tome to type the letter.
I had the letter typed.= I got the letter typed.
He tried to get the car starting.他努力使汽车发动起来.
He had me waiting him for two hours.他让我一直等了他两个小时.