If引导的虚拟语气

2._____,the forest fire would have been discovered much earlier.
A. But for their care B. If they were careful C. Without their care D. If they had been more careful
6.If we ____ the other road, we might have arrived here in time for the meeting.
A. take B. had taken C. took D. have taken
(2)单句改错
①He wouldn' t feel so cold if he was indoors. was→were
5.Had I known about the computer program, a huge amount of time and energy_____.
A. would have been saved B. had been saved C. will be saved D. was saved
+ 动词原形
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
① 过去式（be 通常 用were ）
② should+ 动பைடு நூலகம்原形 ③ were to+ 动词原形
should would could might
+ 动词原形
一、与现在事实相反
②If we had started earlier, we couldn ' t had missed the
first bus. ③If he had time, he will come.
第二个had →have had →has
Thank you !
真实条件句和 虚拟条件句
1.表示客观事实或真理
If you freeze water, it turns to ice. If you eat a lot of chocolate, you put on weight.
从句
主句
if+ 一般现在时，一般现在时
2.表示将来可能发生的事 If he fails in the exam, he will let his parents down. You will certainly succeed if you keep on trying.
1. If I knew his telephone number, I would tell you .
2. If I were you ,I wouldn't be so proud.
二、与过去事实相反
1.If he had taken my advice, he would not have made such a mistake.
1. The printer is of good quality. If it _____break down within the first year , we would repair it at our expense. A. would B. should C. could D. might
2.If I had got there earlier, I would have met her.
三、与将来的事实相反
1.If there were a heavy snow next Sunday, we would not go skating.
2.If she should come, I would tell her about the matter.
从句
主句（陈述句）
if+ 一般现在时，一般将来时（ will+ 动词原形）
3.给某人提建议或命令某人做某事 If you feel sleepy, go to bed. If you want to know how it works, read the
instructions.
从句
主句
if+ 一般现在时，祈使句
4.—The weather has been very hot and dry. —Yes. If it had rained even a drop, things would be much better now! And my vegetables____.
A. wouldn't die B. didn't die C. hadn't died D. wouldn't have died
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。 具体分为三种情况：
时间
从句
主句
与现在事实相反
过去式 （be 通常用were ）
should would could might