He didn't know if he had passed the exam.这句话从语法上来讲对吗?didn't

来源：学生作业帮编辑：作业帮分类：英语作业时间：2024/05/24 20:45:18

He didn't know if he had passed the exam.这句话从语法上来讲对吗?didn't know 能与 if
句末需要加or He didn't know if he had passed the exam or not.

if 与whether 的用法：1.if作“是否”意思的时候,与whether同义,都可引导宾语从句,可以互换.
2.口语中常用if,但是从句中有or not的时候,则只能是用whether,例如：I don‘t know whether it’s snowing or not.
3.whether可以引导主语从句,表与语句,同位语从句,if 则不能,if意为“如果”可以引导条件状语从句,whether则不能,whether可以和不定式连用,if 则不能.4.whether引导的宾语从句可以放在介词后面,if引导的宾语从句则不能

He didn't know if he had passed the exam.这句话从语法上来讲对吗?didn't He didn't know ( John passed the exam,although he didn't study very much for I didn t know it before he told me 这句话对吗 He didn't pass the exam.Instead ,he failed it. he didn't pass the exam. _Instead ______, he failed. he is even (luck),he didn't pass the exam. He didn" t pass the exam ( ) he didn" t study hard. He didn't pass the exam because he didn't study hard.(对划线部分提 He didn't pass the exam because he didn't work( ). Why didn't he pass the exam?I want to know. To my s ,he didn't pass the exam