在大学英语学习中，语法是基础中的基础。掌握好英语语法，不仅能够提高英语水平，还能为听说读写各方面能力的提升打下坚实的基础。以下是大学英语语法中的一些难点及相应的习题，帮助大家更好地理解和掌握英语语法。
一、时态和语态
1. 时态难点
- 现在时：表示经常性或习惯性的动作或状态。
- 过去时：表示过去某个时间发生的动作或状态。
- 将来时：表示将来要发生的动作或状态。
- 现在完成时：表示过去发生的动作或状态对现在产生影响。
- 过去完成时：表示在过去某个时间之前已经完成的动作或状态。
- 将来完成时：表示在将来某个时间之前已经完成的动作或状态。
2. 语态难点
- 被动语态：表示主语是动作的承受者，而主动语态则是主语是动作的执行者。
习题
用正确的时态填空：
- My brother (go) to the cinema every weekend.
- He (finish) his homework before dinner.
- I (plan) to visit my grandparents next weekend.
- The book (publish) last year.
- She (find) the lost key.
将下列句子改为被动语态：
- The teacher corrected my homework.
- They invited me to the party.
- The wind blew the tree over.
- She told me the news.
二、虚拟语气
虚拟语气主要用于表示与事实相反的情况或假设，常用的虚拟语气结构有：
- 与现在事实相反：if + 主语 + were, 主语 + would/could/might/should + 动词原形。
- 与过去事实相反：if + 主语 + had, 主语 + would/could/might/should + have + 过去分词。
- 与将来事实相反：if + 主语 + were to, 主语 + would/could/might/should + 动词原形；if + 主语 + should + 动词原形。
习题
根据句意，用虚拟语气填空：
- If I (be) you, I (not) do that.
- I wish I (have) more time to study English.
- If he (win) the lottery, he (travel) to Europe.
- They would have finished the work by now if they (not) have so many difficulties.
将下列句子改为虚拟语气：
- You should have finished the task earlier.
- If I had enough money, I would buy a car.
- I wish I could fly.
- He would be happy if he could go abroad.
三、名词性从句
名词性从句包括主语从句、宾语从句、表语从句和同位语从句。
1. 主语从句
- 句子结构：It is/was + 被强调部分 + that/who/whom + 从句。
2. 宾语从句
- 句子结构：主语 + 谓语 + 宾语从句。
3. 表语从句
- 句子结构：主语 + 谓语 + 表语从句。
4. 同位语从句
- 句子结构：名词 + 同位语从句。
习题
将下列句子改为名词性从句：
- The reason why he was late is that he got up late.
- What I want to say is that I love you.
- She said that she would come to the party.
- The problem is how to solve it.
选择正确的连接词填空：
- I don’t know ________ she will come.
- It is ________ he will come that matters.
- ________ he said is important.
- ________ we need to discuss is the new plan.
四、倒装句
倒装句是英语中的一种特殊句式，主要有以下几种类型：
- 疑问句倒装：将助动词或情态动词放在主语之前。
- 副词或介词短语引起的倒装：将谓语动词部分或全部置于主语之前。
- 省略if的虚拟倒装：将助动词或情态动词放在主语之前。
习题
将下列句子改为倒装句：
- Are you going to the movies?
- She can speak five languages.
- With the help of my friends, I managed to finish the task.
- If I had known about the party, I would have gone.
选择正确的倒装句形式：
- ________ not you, I would have done it differently.
- ________ hard you are working, you won’t succeed.
- ________ important the test is, I won’t be late.
- ________ late he was, he still finished the work on time.
五、定语从句
定语从句用于修饰名词或代词，主要有以下几种类型：
- 关系代词：who/whom/whose/which/that。
- 关系副词：when/where/why。
习题
用关系代词或关系副词填空：
- The man ________ I met yesterday is my uncle.
- The book ________ you gave me is very interesting.
- I remember the day ________ I first met you.
- He is the person ________ I want to thank.
将下列句子改为定语从句：
- The city where I was born is very beautiful.
- The person who is sitting next to me is my best friend.
- The book that you are reading is very popular.
- I saw the movie that you mentioned yesterday.
六、情态动词
情态动词用来表示能力、可能性、义务、请求等，常用的情态动词有：
- can/could：表示能力、可能性。
- may/might：表示可能性、请求。
- must：表示必须、一定。
- shall/should：表示义务、建议。
- will/would：表示意愿、习惯。
- need：表示需要、必要。
- dare：表示敢于、敢。
习题
用情态动词填空：
- You ________ (not) come to the party yesterday.
- I ________ (can) swim very well.
- You ________ (need) to study harder if you want to pass the exam.
- He ________ (may) be late because of the traffic jam.
将下列句子改为情态动词形式：
- She is very strong.
- You should help your parents.
- I want to watch TV.
- He can speak four languages.
总结
大学英语语法是英语学习的基础，以上列举了一些常见的语法难点和习题。通过学习和练习，相信大家能够更好地掌握英语语法，为英语学习打下坚实的基础。