later，ago, in, after, before 的用法以及区别，特别是用于什么时态，有没有固定的说法

Question

如题所述

Answer 1

later 稍後
ago 之前
in 於 / 在
after 之後 / 在此後
before 在此处

5者中later 和 in 可以用在未来式，其它3个多用於过去式。

例: 10 years later, we all shall be 10 years older.
十年後，我们大家都将会大了十岁。
In 10 years time, we all shall be 10 years older.
再过十年，我们大家都将会大了十岁。

10years ago, the internet was not quite as popular as now.
十年前，网络大不如现在那麼普及。
After the earth quake, half of the town's buildings were destroyed.
地震之後，这个镇半数楼房都已被毁坏。
Before the arrival of computers, people only used paper to file and record things.
在希电脑之前，人们只用纸纪绿挡案。
human didn't used to know how to use fire, later they discovered it by accident.
人类在开始时并不懂得用火，稍後才无意中发明。(这个 later 用作去式)

希望会对你有助。祝你学业进步(若果你还在谂书的话)!!!

Answer 2

later常用在将来时
ago常用在过去时
in常用在将来时
after常用在过去时
before常用在过去时
in和after都是指过了多久 但in用在将来时态，after用在过去时态
如：He will take part in the Olympics in ten years。