宾语补足语,（以下简称宾补）顾名思义,是对宾语的补充,使得句子的内容更完整更充足.句子中是否有宾补,是由谓语动词决定的.有些动词不但要求有宾语,而且要求有宾补,如果丢掉宾补,就不成为句子,或意思走样.宾补一般跟在宾语之后.请看下面的例句,并注意观察：哪些词或词组充当了宾补,把宾补去掉行不行：
1.We all call him Jack.我们大家都称他杰克.Jack 是宾补,用来说明 him.名词充当宾补.
2.He made me angry.他使得我很生气.angry 是宾补,用来说明 me,形容词充当宾补.
3.Put your book down.把你的书放下.down 是宾补,用来说明 your book.副词充当宾补.
4.Put your book into your schoolbag.把你的书放到书包里.into your school bag 是宾补,用来说明 your book.介词短语充当宾补.
5.I will help you to learn English.我将帮助你学英语.to learn English 是宾补,用来说明 you.动词不定式短语充当宾补.
6.Keep the water boiling for ten minutes.保持水沸腾10分钟.boiling 是宾补,用来说明 the water.现在分词充当宾补.
7.She had had the water delivered from the pump to her house.她让人把这水从泵那儿运到她家.delivered 是宾补,用来说明 water.过去分词充当宾补.
主语补足语,（以下简称主补）顾名思义,是对主语的补充,使得句子更加完整.请看下面的例句,并注意观察谓语动词的语态：
1.He was called Jack.他曾被人称为杰克.Jack 是主补.
2.I was made angry.我被人气坏了.angry 是主补.
3.The book was put there.那本书曾被放在那里.there 是主补.
4.The book was thrown into a dustbin.那本书曾被扔进垃圾箱.into a dustben 是主补.
5.The boy was made to work hard 10 hours a day.那男孩曾被迫一天干10小时的重活.to work hard 是主补.
6.The water was kept boiling for ten minutes.水被保持沸腾10分钟.boiling 是主补.
7.The cup was found broken.茶杯被发现已打破了.broken 是主补.
可以看出,这些含有主补的句子都是被动语态.也就是说,一个含有宾补的句子,如果转换成被动语态,那么原来的宾补就变成了主补.与宾补一样,主补也是不能丢掉的.
但是还有一类主补不是出现在被动语态的句子中,例如：
1.He left home a poor worker ten years ago and came back a rich business man.十年前他离家时是个穷工人,但回来时已是富有的生意人.a poor worker 和 a rich business man 均是主补.
2.His father died young.他的父亲死得早.young 是主补.
这种主补在语法界有争议,有的语法学家把这样的句子称为“双重谓语句”,这里就不多讲了.