Question

以下这个语法点怎样记？（如果死记硬背的话马上就会忘掉）

（关于if从句的虚拟语气
1.与过去事实相反，主语是would等+have done，从句是had done
2.与现在事实相反，主语是would等+do，从句是did
3.有将来事实相反，主语是would等+do，从句是did或should+do或were+do
(欢迎高中生或老师解答）
最后一个，were+do改成were+to,我写错了。

Answer 1

答：形式记忆并不难，结合例句记忆更牢固。
列个表格，对记忆有帮助。
　　　　　　　　if 从句谓语 主句谓语
1.现在相反　　　过去式（did）　　　　　　　　　would do
2. 过去相反　　　过过去（had done) would have done
3. 将来相反　　　should do/ were to do/ did would do
注1：.　虚拟条件句的时态就一个字：怪！两个字，奇怪！三个字：不正常！四个字：往过去推！
　现在相反用过去、过去相反过过去、将来相反过将来（should do, be to 也是表将来的，were to　do sth. 也可以这么理解。有时，现在和将来是一个概念，比如：如果我有钱，If I had money, I would do sth. 所以表示与将来情况很可能相反的假设，if 从句也可以用过去式）
注2：主句中的谓语动词时态，先记助动词would+do/ have done,（ 现在和将来是一样的，过去和从句一样，都是完成时态，一个过去完成，一个过去将来完成罢了，只记形式，不记术语）
再扩展知道可以用should, could, might替换would:
　　当主语是第一人称时，可用should代替would, 意思相同，都译作“就会。。。”，
　　如果有“就能够。。。”的意思，则用 could 代替　would
如果是”就可能。。。“的意思，则用might代替　would
注3：If的省略：如果从句中有助动词（包括系动词）were, had, should时，可以通过提前的方式，省去if:
下面是用一些简单基本的句子，来帮助记忆。请将它们背熟了：
1.If I were you, I would try it again.
2.If I had time, I would study French.
3.If you had come yesterday, you would have met him.
4.If it should snow tomorrow, we could ski.
5. Were I to do the work, I should do it some other way.
6. If you had followed my advice, you would be able to finish the work now.
7.But for my brother's help, I would not have finished the work．
如果不是我兄弟帮忙，我就不会完成这项工作。
8. I would have come to see you, but I was too busy yesterday.
注：6为错综时间虚拟条件句。
　　7为隐含条件虚拟语气
　　8为省略条件句（只给出真实情况）的虚拟语气。

Answer 2

主句就记住过去的情况就行了，将来和现在用法相同，从句后退一个时态

Answer 3

从句很好记，退后一个时态就行了，过去对应过去完成时。。。
主句嘛，都是would+。。。 与过去相反主句和从句都是完成时
现在和将来时一样的，只是将来从句有三种形式，记清就好，其实用多了就自然记到了，多做点虚拟语气方面的练习嘛

Answer 4

虚拟语气简记为3D（读做“帝”）1d（读作“的”）。 D是指could，would，should，d 是指从句中有d的那个词，对于1，完成时对应完成时，就是主句从句都是完成时，主句因为有情态动词所以是现在完成时，从句对应过去完成时。对于2，就很简单啦。对于3，在记住2 的基础上再记住可以有should do和were to do可以记为助动词形式一种，be动词形式一种，情态动词形式一种。多记几遍就记住了。楼上说的很对~~~~，希望我的回答对你有帮助。

Answer 5

1.If I were you, I would try it again.改:if i were you, i would have tried it again. 注:通常是i was 但是i were这里也对,因为这个情况是不可能发生的所以i were.
2.If I had time, I would study French.
改: if i had time, i would have studied French.
3.If you had come yesterday, you would have met him.
改:if you came yesterday, you would have met him.
4.If it should snow tomorrow, we could ski.
改:if it snows tomorrow, then we will be able to ski. could is in the past.
5. Were I to do the work, I should do it some other way.
改:if i were assigned the work, i would have done it the other ways.
6. If you had followed my advice, you would be able to finish the work now.
改:if you followed my advice, you would have finished the work by now.
7.But for my brother's help, I would not have finished the work．
改:if it is not for my brother's help, i would not have finished the work.
8. I would have come to see you, but I was too busy yesterday.

楼上的句子差不多全错了. 但是这些语法很多人都不注意所以错了也是平常的.
I wouldn't have done what you did.我不会这样做你做过(did)的事.
if you do it now, i would appreciate it. 如果你现在做,我很感激.
在将来发生的事就用will而不是would. i won't(will not) do it. 我不会这样做.

1.与过去事实相反，主语是would等+have done，从句是had done
2.与现在事实相反，主语是would等+do，从句是did
3.有将来事实相反，主语是would等+do，从句是did或should+do或were+do
你这些东西不知道哪里来的,但我肯定这些从语不能和这些主语共存同一个句子上,就算写成了也是错的如同楼上. 如果是分开句子写就可以(有可能)写成也不造成语法问题.

追问

难道国标本教科书上的也有错？
我又把改前和改后的句子放在Word上检查语法，发现都对。

追答

Word的语法检查一点都不对的,我写英文文章都是用word,漏洞很多. 中国的标准书我也不知道标不标准...如果这样的错误全是,那么那本书很垃圾.