补语（Complement）
（1）英语中有些及物动词虽然有了宾语，但句子的意思仍不完整，还需要在宾语之后增加一个成分以补足其意义，这种成分叫宾语补语。能作宾语补语的有名词、形容词、介词短语、副词、动词不定式、分词。
They appointed him head of the department. 他们任命他当部门主任。
They painted the wall blue. 他们把墙刷成蓝色。
People regard the sun as the chief source of heat and light. 人们认为太阳是主要的热源和光源。
（2）当带有宾语的句子变成被动语态，句子原来的宾语就成了主语，而原来的宾补也就随之成了主补。试比较：
They appointed him head of the department.
He was appointed head of the department.
They painted the wall blue.
The wall was painted blue.
People regard the sun as the chief source of heat and light.
The sun is regarded as the chief source of heat and light.