介词是一种虚词,在句中不单独作任何句子成分,只表示其后的名词或相当于名词的词语与其他句子成分的关系。
介词后的名词,或相当于名词的其他词组、短语或从句,称为介词宾语。
介词和介词宾语一起构成介词短语。介词短语在句中主要用作定语、状语、表语和宾语补足语。
The boy over there is my brother.(作定语)
A friend in need is a friend indeed.(作定语)
I shall meet you at the entrance of Qianmen Hotel.(作地点状语)
To their surprise, they saw not locusts, but seagulls.(作原因状语)
I’ll be in the office every afternoon.(作表语)
The farmer made the king out of the water.(作宾语补足语)
I found everything in good order(作宾语补足语)