介 词 1 表示时间的介词：at, in, on, before, to, from, by, till, until, after, for, since 等。2 表示地点，位置，方向的介词：next, to, in, in front of, on , out of, at, above, over, into, near, between, under, up, across, by, down, from, around, behind, beside等3 表示原因，理由的介词：for, as, at, from 等4 表示方式的介词：on, in, by, with 等。常用介词辨析1 表示时间的in, on, at, after1) in 的用法。用于早晨、下午、傍晚。In the morning/afternoon/evening用于月、年、季节等。In March, in 1986, in spring用于一段时间后。In a week, in a years time, in two hour
