if引导的条件状从

1、if 引导的条件状从和虚拟语气3.I wonder if its similar to the Water Festival of the Dai people in Yunnan Provinceif=whether 是否 引导宾语从句if 可以引导条件状语从句 if引导的条件状语从句，如果从句谈论的是一个有可能发生的事实及其产生的相关结果 ，那么主句要用一般将来时，从句要用一般现在时。If it does not rain tomorrow,we will have a picnic.If he walks to school at 6:50 am,he will be late for

2、school.If you ask him,he will help youif引导的条件状语从句，如果从句谈论的是重复发生和预示要发生的情景和事件，那么主句要用一般现在时，从句要用一般现在时。If you heat ice it turns to waterIf bears are in danger,they attack peopleif引导的条件状语从句，从句用一般现在时，主句用must/should/may/might/can,的用法If the fog gets thicker the people may/might be diverted.If it stops snowing

3、 we can go outIf引导条件状语从句的歌诀if 条件句不一般，几个要点要牢记，条件句，放在前，逗号放在句中间，条件句表可能，主句多用将来时，条件句表事实，主句常用现在时。if引导的虚拟语气表示不可实现的条件或根本不存在的条件.从句用一般过去时,主句为would/should/could/might+v原 表示与现在事实相反If I were you,I would invite him to the party.If I were a bird,I would fly in the sky.If it weremt snowing,we couldnt stady in the h

4、ouse.If I were a teacher,I would be strict with my studentsIf I got up early in the morning,I wouldnt miss the trainIf I had time,I would study French.从句用从句用had+v-ed,had+v-ed, 主句为主句为would/should/could/might+have+would/should/could/might+have+v-edv-ed 表示与表示与过去事实相反过去事实相反If he had come here yesterday,h

5、e would have seen his old friends.If it had rained yesterday,we would have stayed at home.If he had been faithful,he might have been promoted.If I had known that you were coming,I would have picked you up at the airport.If we had had enough rain last year,we could have gained a good harvest .从句用.过去式.should+v原.were to+v原 主句用would/should/could/might+v原 表示与将来事实相反If it snowed tomorrow,our plan would be postponed.If we should come tomorrow,we could m