香港铜锣湾集团资质:非真实条件句是什么啊

非真实条件句

1）时态：可以表示过去，现在和将来的情况。它的基本特点是时态退后。
a. 同现在事实相反的假设。
句型 ： 条件从句 主句
一般过去时 should( would) +动词原形
If they were here, they would help you.

b. 表示于过去事实相反的假设。
句型： 条件从句 主句
过去完成时 should(would) have+ 过去分词
If she had worked harder, she would have succeeded.
The rice would not have been burnt if you had been more careful.
If my lawyer had been here last Saturday, he would have prevented me from going.

If he had come yesterday, I should / would have told him about it.
含义：He did not come yesterday, so I did not tell him about it.
If he had not been ill and missed many classes, he would have made greater progress.
含义： He was ill and missed many lessons, so he did not make greater progress.

c. 表示对将来的假想
句型： 条件从句 主句
一般过去时 should+ 动词原形
were+ 不定式 would + 动词原形
should+ 动词原形
If you succeeded, everything would be all right.
If you should succeed, everything would be all right.
If you were to succeed, everything would be all right.

一、虚拟语气表示一种不能实现的假设。该语法主要用于if条件状语从句。也可用于主语从句、表语从句、宾语从句等。
二、if条件状语从句中虚拟语气的判断
判断是真实条件句还是非真实条件句。只有在非真实条件句中才使用虚拟语气。通过句子意思，看假设的条件是否能够实现，能够实现是真实条件句，不能使用虚拟语气；假设的条件不能实现则是非真实条件句，要用虚拟语气。
判断这个假设是与哪个事实相反。通常有三种情况：①与过去事实相反。②与现在事实相反。③与将来事实可能相反。
三、“后退一步法”
后退一步法是指在准确地判断了该句与哪一事实相反后，按虚拟语气的后退一步法处理从句谓语动词的时态。即：在非真实条件状语从句中，谓语动词按正常情况“后退一步”。也就是：
①与过去事实相反，在从句中用过去完成时形式表示。
②与现在事实相反，在从句中用过去一般时形式表示。
③与将来事实可能相反，在从句中用过去将来时形式表示。
主句中则用情态动词would, should, could 等加一个与从句一致的动词形式。
例：If I had come her yesterday, I would have seen him.
If I were a teacher, I would be strict with my students.
If it should snow tomorrow, they couldn't go out.
四、注意事项
①if条件句中如有were, should, had，可以省去if，并使用倒装语序。
②在现代英语中if条件状与从句中的谓语动词如果是be其过去形式一般用were。

●宾语从句中的虚拟语气
一、wish 后面宾语从句中的虚拟语气
wish 后面宾语从句中的虚拟语气，按“后退一步法”处理从句的谓语动词。注意：与哪个事实相反，不能以主句的时态为判断依据，而是根据从句的意义判断。
二、表示“要求、建议、命令”等动词后面的宾语从句中的虚拟语气
从句中用“should + 动词原形”构成。而且should可以省去。用于此结构的动词有：advise, direct, agree, ask, demand, decide, desire, insist, order, prefer, propose, request, suggest等。
注意：当insist表示“坚持认为”、suggest表示“表明，显示”时，不用虚拟语气。
The look on his face suggested that he was quite satisfied with what I had done for him.
He insisted that he was honest.
三、would rather ＋从句
在这种结构中，从句的位于动词用过去形式表示虚拟。
I would rather you did this instead of me.
●主语从句中的虚拟语气
一、It be + 形容词 + that ．．．（should）．．． 用于该句型的形容词是：necessary, good, inportant, right, wrong, better, natural, proper, funny, strange, surprising ．<br>
一些名词也可以用于 在该结构中。如：a pity， no wonder．．．．<br>
二、It be + 过去分词 + that ．．．（should）．．．．<br>
用于该结构中的过去分词是表示“建议、请求、命令”等词的过去分词。如：desired， suggested， requested， ordered， proposed等。<br>
三、It is time（about time， high time）that ．．．（过去式动词形式或should＋动词原形）．．．．<br>
It is high time I went home now. = It is high time I should go home now.<br>
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●表语从句、同位语从句中的虚拟语气<br>
在suggestion， proposal， order， plan， idea， advice， decision等需要有内涵的名词后面的表语从句、同位语从句中，要使用虚拟语气。其谓语动词应用：should＋原形动词。另外连接从句的that不能省略。<br>
例：My suggestion is that weshould go there at once.<br>
What do you think of his proposal that we should put on a play at the English evening?

参考资料：http://www.mryuan.net/ShowArticle.asp?ArticleID=55
参考资料：http://zhidao.baidu.com/question/1182688.html

　　非真实条件句
　　1）时态：可以表示过去，现在和将来的情况。它的基本特点是时态退后。
　　a.　同现在事实相反的假设。
　　句型 ： 条件从句　主句
　　一般过去时　should( would) +动词原形
　　If they were here, they would help you.
　　b.　表示与过去事实相反的假设。
　　句型： 条件从句　主句　
　　过去完成时　should(would) have+ 过去分词
　　If she had worked harder, she would have succeeded.　
　　The rice would not have been burnt if you had been more careful.　
　　If my lawyer had been here last Saturday, he would have prevented me from going.
　　If he had come yesterday, I should / would have told him about it.
　　含义：He did not come yesterday, so I did not tell him about it.
　　If he had not been ill and missed many classes, he would have made greater progress.
　　含义： He was ill and missed many lessons, so he did not make greater progress.　
　　c.　表示对将来的假想，与现在的现实相反。
　　句型：　条件从句　主句
　　一般过去时　should+ 动词原形
　　were+ 不定式　would + 动词原形 should+ 动词原形
　　If you succeeded, everything would be all right.
　　If you should succeed, everything would be all right.
　　If you were to succeed, everything would be all right.

如果后面说的事情不可能发生

举例：If I were you,...