网友有这样的疑问,说明对介词动词(即不及物动词+介词构成的短语动词)不够了解。
当不及物动词+介词构成一个短语动词时,二者就被视为一个整体,一个新的及物动词。后接的名词被分析为这个及物动词的宾语,而且还可以有被动语态。例如:
His brother looked after him.
He was looked after by his brother. 网友现在想一想,在这个被动语态句子中,介词after的宾语在哪里呢?不及物动词look是没有宾语的,look after之所以能接宾语,是因为介词才能后接名词,既然二者构成了短语动词,after就不再看成介词,而是look after 这个及物动词的一部分。look after的被动语态形式就是be looked after. 其宾语在被动结构中就是主语了,after就不能再后接名词了。
take care of sb的被动语态形式为:be taken care of,介词的宾语成了句子的主语,当然of后面不可能再加名词了。
I took care of him very well. He was well taken care of.
Being taken care of作状语时,句子的主语就是分词短语的逻辑主语。