1、FIRSTSECONDTHIRDZEROIf I am late for school,my teacher gets angry.If clauseMain clauseMain clauseIf+Present simplePresent simpleIf I oversleep I miss the bus.If I miss the bus,I am late for school.If I am late for school,my teacher gets angry.If I go to London,I will see the Big Ben.If clauseMain cl
2、auseIf+Present tensewill/can/may/must+verbIf I go to London I will see the Big Ben.If I go to Buckingham Palace,I can take a photo of the Royal Guard.If you go to London,you must look right before crossing a streetIf clauseMain clauseIf+Past Simplewould/could/might+verbIf I were an astronaut,I would
3、 travel in a spaceship.If I were an astronaut,I would travel in a spaceship.If I travelled in a spaceship,I would go to Mars.Nice to meet you!#If I went to Mars,I would meet a Martian.If I met a Martian,I wouldnt understand him.?#IfI IfI avedavedIf I didnt understand him,I would come back to the Ear
4、th.If I had studied hard,I would have passed my exams.If clauseMain clauseIf+Past Perfect tensewould/could/might+have+past participleIIf you had studied hard,you wouldnt have failed your exam.IIf you had passed your exam,you could have gone to the beach.IIf I had gone to the beach,I would have made sand castles.