如题所述
第1个回答 2012-04-20
1、对现在情况的假设:表示说话时不存在或与事实相反的情况。形式:If+主语+did,主语+should/ would /could +do.例句:If you knew english well,you would be able to talk with foreigners freely.
2、对过去情况的假设:表示与过去事实相反的情况。形式:if+主语+had done,主语+should/would /could+have done.例句:if i had not studied hard ,i might have failed in the exam.(事实是我通过考试了)
3、对将来情况的假设:表示将来实现可能性不大的情况。形式:if+主语+did/were to do /should do,主语+should /would /could do.例句:if he should change his mind ,what would we do?
if的省略:在正式文体中,有时可把虚拟条件句中的连词if省去,这时从句需要采用倒装语序,即:将were,had,should等助动词提到主语前面,主句不做任何变化。例句:should it rain tomorrow,we would staly at home.
错综时间:所谓错综时间是指主句和从句的动作不是发生在同一时间。这时,需要根据意思选用表示不同时间的虚拟语气形式。例句:if i were you ,i would have taken his advice.(从句表示现在时间,主句表示过去时间),我要是你,就听他的忠告了。
2、对过去情况的假设:表示与过去事实相反的情况。形式:if+主语+had done,主语+should/would /could+have done.例句:if i had not studied hard ,i might have failed in the exam.(事实是我通过考试了)
3、对将来情况的假设:表示将来实现可能性不大的情况。形式:if+主语+did/were to do /should do,主语+should /would /could do.例句:if he should change his mind ,what would we do?
if的省略:在正式文体中,有时可把虚拟条件句中的连词if省去,这时从句需要采用倒装语序,即:将were,had,should等助动词提到主语前面,主句不做任何变化。例句:should it rain tomorrow,we would staly at home.
错综时间:所谓错综时间是指主句和从句的动作不是发生在同一时间。这时,需要根据意思选用表示不同时间的虚拟语气形式。例句:if i were you ,i would have taken his advice.(从句表示现在时间,主句表示过去时间),我要是你,就听他的忠告了。