时态有五个问题要注意的，即格式，含义，比较，统一和活用。在实际应用中，时态的基本规律并不复杂，只要多想多用，很快就可以掌握的，至于更多的变化，也完全可以在以后的学习中逐步掌握的。下面我们列举出15种在托福写作中经常用到，又容易出错的语法，希望同学们牢记。

　　托福写作时态（写作常用且常错）：

　　1.一般现在时：表示真理性，经常性，习惯性，普遍性。[在口语里常用，在叙事性文章和故事里很少用]

　　例句：1.The earth is smaller than the sun. [状态][真理性]

　　2.Tom gets up early every morning. [动作][经常性和习惯性]

　　3.Everybody knows him. [普遍性]

　　2.过去时：表示过去某一时间里发生的动作或状态。 [叙事性的文章和故事里最常用的时态]。

　　例句：1.Yesterday we went to the park.[动作]

　　2.The book was there ten minutes ago. [状态]

　　3.将来时：表示将来某一时间里发生的动作或状态。

　　例句：1.Tom will help you tomorrow. [动作]

　　2.We shall be here in time next time. [状态]

　　4.过去将来时：表示从过去某一时间看将在以后某一时间里发生的动作或状态。[注意不要跟现在联系起来]

　　例句：1.Ten years ago, Mary said she would finish the work in a few days. [动作]

　　2. Yesterday he thought you would be a good player after five years. [状态]

　　5.现在完成时：表示在现在之前就已经完成的动作或状态[要特别注意不包括现在]。

　　例句：1.We have done our homework. [动作]

　　2.He has been a doctor now. .[状态]

　　6.过去完成时: 表示在过去某时之前就已经完成的动作或状态。

　　例句：1.Three days ago he had already finished his homework. [动作]

　　2.When he was a boy, he had already been a head of the boys. [状态]

　　7.将来完成时：表示在将来某时之前将完成的动作或状态。

　　例句：1.Tomorrow morning, I will have cleaned the windows. [动作]

　　2.Next Sunday, he will have been a new doctor. [状态]

　　8.过去将来完成时:表示在过去某一时间之前本该完成的动作或状态。[一般用于虚拟语态]

　　例句：1.If he had worked hard enough, he would have built a new house. [动作] [实际情况是因为他不够努力，所以新房子连影子都没有]

　　2.If he were alive, he would have been a doctor now. .[状态][实际情况是他已经去世，所以永远成不了医生]

　　9.现在进行时：在现在之前开始，以后还要延续一段时间的动作。[要注意只有延续性动词可以用进行时]。

　　例句：Tom is reading a book.

　　10.过去进行时：在过去某时之前开始，以后还要延续一段时间的动作。[要注意只有延续性动词可以用进行时]。

　　例句：The dog was eating a bone.

　　11.将来进行时：在将来某时之前开始，以后还要延续一段时间的动作。[要注意只有延续性动词可以用进行时]。

　　例句：At ten tomorrow morning, I will be writing the letter for you.

　　12.过去将来进行时：从过去某时来看将再以后某时之前开始，以后还要延续一段时间的动作。[要注意只有延续性动词可以用进行时]。

　　例句：Jack told me that he would be working hard the next year.

　　13.现在完成进行时：在现在之前就已经完成并且还要延续下去的动作。[较少用]

　　例句：Tom has been reading this book for over ten hours.

　　14.过去完成进行时：在过去某时之前就已经完成并且还要延续下去的动作。{很少用}

　　例句：The workers had been building the railway then.

　　15.将来完成进行时：在将来某时之前就已经完成并且还要延续下去的动作。{很少用}

　　例句：They will have been making their efforts after that time.

　　16.过去将来完成进行时：在过去某时之前看来将来某时应该已经完成并且还要延续下去的动作。{很少用}

　　例句：We thought they would have been doing physical training till then.

　　能正确运用这些时态之后我们又会发现，其实每篇文章里时态的搭配都可以有多种方案，就像我们每个人的衣着可以有很多种搭配一样，我们时态的用法也可以有多种搭配方案，只要能符合表现文章的主题的需要，就应该说是正确的。至于哪种是的方案，则各人有个人的看法，所谓仁者见仁，智者见智了。