would/could/
might+动词原形
9
注意： 在if I /he/she/it 之后, 可用were代替was。 两者在意义上没有区别, 但是were更为正 式, 特别是在称述心存怀疑的事情时: If she were ready, we would go.
10
在与将来事实相反的条件从句中,我们 可以用were to或should +do来表示,如: If I were to fail my English test, I would have to take it again at the end of the term. If he should come tomorrow, I would talk to him about it.
17
2. 用相当于if 的其他连词表示虚拟结构 在条件从句中除最常见的连词之外,尚 有下列连词: otherwise; in case; but that; on condition that; unless; suppose/supposing (that); so long as; provided/providing (that)
3
Observe the following sentences and tell Whether they are real or unreal conditional clauses.
4
If we go on polluting the world, it won’t be fit for us to live in.
15
含蓄条件句 有时一个假设的情况并不用条件从句表示, 而用其它方式来表示,这样的句子叫含蓄 条件句。 1.用with, without等介词短语或分词短语
或者独立主格结构来代替条件从句。
16
e.g. We might have died without your help. =We might have died if you hadn’t helped us. Having known in time, we could have stopped it. = If we had known in time, we could stopped it.
13
错综时间条件句 有时非真实条件句中, 主句谓语动词所表 示的动作和条件从句中谓语动词所表示 的动作并不同时发生, 这时动词的形式并 不完全按照上述表格来进行, 而需要按照 各自的时间来调整, 这样的句子就叫错综 时间条件句。
14
e.g. If you had followed the doctor’s advice, then you would be all right now. If I hadn’t finished my composition by now, I would be working on it tomorrow. If she had prepared well for her lessons yesterday, she wouldn’t have so many difficulties now.
1
Grammar and usage Unreal conditionals
虚拟语气中的非真实条件句
虚拟语气的介绍 虚拟语气可用于条件句和其它一些从句中。 虚拟语气用于条件句中比较多, 情况也比较 复杂, 所以要特别加以注意, 首先要判断一 下是否应该用虚拟语气, 因为条件句分为两 种, 一种是真实条件句, 一种是非真实条件 句, 只有在非真实条件句中才用虚拟语气, 在真实条件句中, 要用陈述语气。
12
If I were in your position, I would do it better. = Were I in your position, I would do it better. If they had made preparations, they would have succeeded. =Had they made preparations, they would have succeeded.
11
虚拟条件句中的省略与倒装 在非真实条件句中,如果有were, had, should, 我们可以将if should meet her, I would tell her. = Should I meet her, I would tell her.
6
非真实条件句的时态表达 如果假设的情况完全不存在或者实现的 可能性很小,可以说几乎没有时,就需要 用虚拟语气来表达,也就是说,这时的条 件句是非真实的条件句。此时的句子时 态比真实条件句中的时态后退一步。
7
虚拟语气
1. 条件从句和主句中的虚拟语气
时间
从句
主句
与现在事 If +主语+动 主语+should/
If you are busy doing your homework, I won’t interrupt you.
If you have finished cleaning the classroom, you can go home now. (Under these conditions, the things are sure to happen.)
实相反 词的过去式 would/could/might
(be-were)… +动词原形
与过去事 If+主语+had 主语+should/would 实相反 +过去分词 /could/might +
have+过去分词
8
与将来事
If+主语+were to/(should) +
主语+should/
实相反 动词原形
5
If there were a lot of good restaurants in the city, this would make it more attractive. (There aren’t many good restaurant now.) If a lot of people spoke English, it would be very helpful for tourists. (Not many people can speak English now.)