if引导的虚拟语气.pptx

真实条件句和虚拟条件句
第一页，共17页。
第二页，共17页。
If you freeze water, it turns to ice. If you eat a lot of chocolate, you put on weight.
真实条件句
从句 主句
if+一般如今时，一般如今时
第三页，共17页。

If he fails in the exam, he will let his parents down.
You will certainly succeed if you keep on trying.
从句 主句〔陈述句〕
if+一般如今时，一般将来时〔will+动词原形〕
第四页，共17页。
 If you feel sleepy, go to bed.
If you want to know how it works, read the instructions.
从句 主句
if+一般如今时，祈使句
第五页，共17页。
If引导的虚拟条件句，即非真实条件句，表示条件句所表示的条件根本不可能实现或实现的可能性很小。根据动作发生时间的不同，含有非真实条件句的复合句的主从句的谓语动词采用不同的表达方式。详细分为三种情况：
虚拟条件句
第六页，共17页。
时间
从句
主句
与现在事实相反
过去式
（be 通常用were）
should
would
could +动词原形
might
与过去事实相反
had+过去分词
should
would
could +have+过去分词
might
与将来事实相反
过去式（be 通常用were）
should+动词原形
were to+动词原形
should
would
could +动词原形
might
第七页，共17页。
一、与如今事实相反
If I knew his telephone number, I would tell you .
If I were you ,I wouldn't be so proud.
第八页，共17页。
二、与过去事实相反 he had taken my advice, he would not have made such a mistake. I had got there earlier, I would have met her.
第九页，共17页。
三、与将来的事实相反 there were a heavy snow next Sunday, we would not go skating. she should come, I would tell her about the matter.
第十页，共17页。