这三个词都有“在……之后”的意义,区别如下:
1)in表示从现在开始一段时间以后,它往往和一般将来时肯定句连用.如:
I'm coming back in a minute.我一会儿就回来.
He will reach here in two days.他两天后将到达这里.
2)after表示以过去的某一时间为起点,“过……之后”,其后既可接时间点,又可接时间段.但是,如果after用于一般将来时,那么其后应接时间点.如:
He left there after two o'clock that afternoon.那天下午两点以后,他离开了那儿.
They started to go again after two days.两天以后,他们又走了.
I think he'll come here after three o'clock.我想他三点钟后将来这儿.
3)later指“以后”、“后来”,可以指过去,也可指将来,是副词,常常放在时间段的名词之后.如:
Three days later he got to Beijing.
=After three days he got to Beijing.他三天以后到达了北京.