介词的用法 介词(preposition) ：也叫前置词。在英语里，它的搭配能力最强。但不能单独做句子成分,需和名词或代词（或相当于名词的其他词类、短语及从句）构成介词短语，才能在句中充当成分。一、介词的种类（1）简单介词：about, across, after, against, among, around, at, before, behind, below, beside, but, by, down, during, for, from, in, of, on, over, near, round, since, to, under, up, with等等。（2）合成介词：inside, into, outside, throughout, upon, without, within（3）介词短语：according to, along with, apart from, because of, in front of, in spite of, instead of, owing to, up to, with regard to 等等。二、介词短语的作用 介词不单独作句子
