虚拟语气相关知识

急~！！！

1).概念
 虚拟语气是一种动词形式，表示说话人的一种愿望，假设，怀疑，猜测, 建议等含义，虚拟语气所表示的含义不是客观存在的事实。
2).在条件句中的应用
　 条件句可分为两类，一类为真实条件句，一类为非真实条件句。非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。
虚拟条件句
条件状语从句是非真实情况，在这种情况下要用虚拟语气。
1、条件从句与现在事实不一致，其句型为：
If 主语＋动词过去式/ were，主语＋would（could, should, 或might）＋动词原形，例如：
 If I were you, I would study hard.
 If it rained, I would not be here now.
2、条件从句与过去事实不一致，句型为：
If 主语＋had＋过去分词，主语＋would（could, should, 或might）＋have＋过去分词，如：
 If the doctor had come last night, the boy would have been saved.
 If I had not studied hard, I would have failed in the exam last term.
3、条件从句与将来事实不一致，句型为：
If 主语+动词过去式/should+动词原形/were to do，主语＋would（could…）＋ 动词原形，例如：
 If it should rain tomorrow, we would stay at home.
 If I were to go to the moon one day, I could see it with my own eyes.
 If you missed the film tonight, you would feel sorry.
注：虚拟条件句中如果含有were, should或had(助动词),可将were, should 或had提前，把if去掉，实行倒装。但要注意，在这种情况下句首不用动词的缩略形式。如我们可以说Were I not to do,而不能说Weren’t I to go.

虚拟语气(Subjunctive Mood)是一种特殊的动词形式，表示说话人所说的话并不是事实，只是一种假设、愿望、怀疑或推测。I wish I were a bird. I wish I would be rich in the future, If he smoked less, his cough might be well soon.