if 表是否时主句与从句的时态是什么?请举些例句.

2个回答

当if当是否讲时,引导的是宾语从句,那么if从句的时态要与主句联系起来.1、当主句是过去时态时,从句要用相应的某一种过去时态.如：He asked me if I was a student.He wanted to know if you lived in the city.2、当主句是现在时态时,从句可以根据需要使用任何一种时态.如：I don't know if he will come tomorrow.please tell me if you have a girlfriend.