简单举四个例子 I know you are right. I knew you were right. I have known you are right. I had known you were right. 补:讲一个大多数同学忽略的事实,现在完成时属于现在时,过去完成时属于过去时,还是举例子I couldn't remember where I --A----yesteday.A,went B have gone 明白前面所讲现在完成时属于现在时的同学肯定不会问为什么不选B了。
第2个回答 2019-08-27
宾语从句的时态是这样规定的: 主句为过去式,从句需用过去时的某种形式,如一般过去时,过去进行时,过去将来时等(真理、客观事实除外);主句为现在时,从句可根据需要用所需时态。 we all know that he has studied english since 1998. we believed that he had earned enough money to build a house. the teacher told us that the sun rises in the east.