abbr.it had 已经，it would 将要

It's raining outside, better take an umbrella.
外面在下雨，还是带上把伞吧。
It's been a long time since we last met.
我们上次见面已经很久了。
It's not the end of the world if you fail the exam.
考试不及格并不是世界末日。
It's no use crying over spilt milk.
覆水难收。
It's getting late, we should head back now.
天色已晚，我们应该回去了。
It's always darkest before the dawn.
黎明前总是最黑暗的。
It's never too late to learn.
活到老学到老。
It's a small world after all.
世界毕竟很小。
It's a piece of cake.
小菜一碟。
It's a long story.
说来话长。