有关宾语从句,1·主句用一般现在时,从句可用任意时.2·主句用过去时,从句用过去某个时态.3·主句用过去时,从句是真理时

1.I don’t know if there will be a bus any more.
我不知道是否还会有公交车.
I 是主语 ,don't是否定助动词,且don't know是谓语部分,之后if引导的则是宾语从句,主句用一般现在时是指现在不知道之后,也就是将来的那个时间会不会有车来.
2.I only knew he was studying in a western country,but I didn’t know what country he was in.
我只知道他当时在西方的一个国家读书,可不知道是哪个国家.以下同上一样分析就好了.
3.The teacher said that the moon goes around the earth yesterday.
老师昨天说月亮绕着地球转.

宾语从句
在句子中起宾语作用的从句叫做宾语从句.宾语从句分为三类:动词的宾语从句,介词的宾语从句和形容词的宾语从句.
时态：1·主句用一般现在时，从句可用任意时。
2·主句用过去时，从句用过去某个时态。
3·主句用过去时，从句是真理时，只用一般现在时。
1.宾语从句的连接词
从属连词
连接宾语从句的从属连词主要有that,if,whether...

1.He often thinks that his friends are friendly to him.
2.He said that he had seen him last month.
3.My teacher told us that the earth goes around the sun.