Question

Look at the clock! It is time _____ home.

这里使用we went 过去的原因是什么

Answer 1

It's (high/ about) time +从句
从句中的谓语动词有两种形式，或者用动词的过去式(be用were)；或者用shoud + 动词原形（should不能省略)。此句型为虚拟语气句型，表示“现在某人该做某事了”。含有该事早该去做而未做，现在去做似乎都为时已晚的意思。例： It's time （that）we went to bed. 我们该去睡觉了。 It's high time that the article were published. 发表这篇文章是适时的。 It's time you should do cleaning. 你该去打扫卫生了。

Answer 2

It is time 有 4 个不同用法：

1) It is time + infinitive（动词不定式）:
It's time to start the race. (现在是时候开始比赛了。)
It is time to take a break. (现在是时候休息一会儿了。)

2) It is time + for + object + infinitive（宾语+ 动词不定式）:
It's time for us to start the journey. (现在是时候让我们开始旅程了。)
It's time for you to go. (你现在是时候去了。)

3) It is time + for + noun（名词为宾语）:
It's time for breakfast. (现在是时候吃早餐了。)
It's time for a break. (现在是时候休息一会儿了。)

4) It is time + subject + past subjunctive（过去式 - 虚拟句）:
It's time we went home.
It is time he came here.
It is time the police took action.
It's time you made up your mind.
上面第4类 (past subjunctive)，我们用过去式动词 (simple past) 来说现在应该做却还没有做的事情，那过去式动词不是真正的过去式(虽然写法一样)，这是带有假设意思的过去式，这个用法叫 unreal past 或是 past subjunctive。
句子
It's time we went home. 是该回家的时候了
就是这种用法。

我是加拿大人，前英语老师。