1. It's time + that + v-ed，表示与现在或将来的情况相反，最普通的虚拟语气用法。

   I think it is high time that you made up your mind. 我认为到了你作出决定的时候了。

2. It's time + that + sb. + should + v，英国人的用法，语气比前者强烈。

   It's high time they should take you seriously and they know it.到了他们认真对待你的时候了，他们应该清楚这一点。

3. It's time + that + v，美式用法。

   It's high time we sum up our results.我们应该把结果总结一下了。

4. It' time that + was / were doing，与将来时相反，只用于少数动词：come, go, leave, start, stay。         

   It's high time that we were leaving.我们该走了。

   It's time I were going. 我该走了。

5. It's the first / third time ＋ that-clause

 1). 主句谓语用is / will be时，从句用现在完成时。

 2). 主句谓语用was时，从句用过去完成时，必须与另外一种句型分开。

   It will be the second time I've met him. 这将是我第二次遇见他。

   It was the first time this year he hadn't attended the class meeting.这是他今年第一次缺席班会。

   以下例句说明的是另外一种句型。

   The first time Jack took the exam, he failed, but he passed the second time.杰克第一次参加考试，没考过，但是第二次他考过了。

   The third time you try, you will succeed.再试第三次，你就会成功。