表语（predicative)是用来说明主语的身份、特征和状态的.它的位置在连系动词（be,become,appear,look,seem等）之后.
可用作表语的词有：
He is careful.(是形容词作表语,千万别用副词carefully)
He is a boy.(名词)
He is in.（副词）
= He is at home.（介词短语）
This food tastes good.( 形容词good作表语,千万别用副词well)
That was what I said.(句子作表语,用的是表语从句)
It's me.(代词）
He is twelve.(数词）
To see is to believe.(（动词不定式)
Seeing is believing.（现在分词）
His watch is broken.(过去分词)
宾语补足语是补充说明宾语的成分
1、常接形容词作宾语补足语的动词有：keep,make,find等.如：We must keep our classroom clean.
2、常接名词作宾语补足语的动词有：call,name,make,think等.如：We call them mooncakes.
3、常接动词-ing形式作宾语补足语的动词有：see,watch,hear,find,keep等.如：In the country,we can hear birds singing.
4、常接介词短语作宾语补足语的动词有：keep,find,leave等.如：I left my pen on my desk at home.
5、常接带to的动词不定式作宾语补足语的动词有：ask,tell,want,teach,wish等；接不带to的动词不定式作宾语补足语的动词有：see,watch,hear,make,let等.如：I often see him play football.
She often asks me to help her.
注：help后面作宾语补足语的动词不定式可以带to也可以不带to.如：
I often help my mother(to) do some housework.