who are you waiting for?是主谓宾但是his job is cleaning the office.却是主系表,
问题描述：
who are you waiting for?是主谓宾但是his job is cleaning the office.却是主系表,
不要解释成主谓宾是什么主系表是什么.
答
who are you waiting for?的一般现在时是“Who do you wait for?”这下楼主可明白为什么说它是主谓宾结构吧?
His job is cleaning the office 是一般现在时.这里的cleaning是动名词,与前面的is连在一起组成表语.