“动词+介词”的动词短语,其宾语放在短语之后.例如：
He can look after himself.
“动词+副词”的动词短语,其宾语放在短语之后或短语中间都行.例如：
Can you give back my book?
Can you give my book back
但是,如果是代词宾语,只能放在短语中间.例如：
Please turn it down.(对)
Please turn down it.(错）
这类副词通常有下列九个：away,back,down,up,in,on,off,over,out.