谁能解释下宾语从句的时态问题 比如主句一般现在时 从句用什么 主句一般过去式从句用什么 还有什么其他的

1、主句动词为一般现在时的，宾语从句用“直陈语气或时态”：就是“什么时候发生的，就用这个时态：
a. I know (that) he is kind.
b. I know that he works in a company.
c. I know that he will go(= is going) to study in the US next year.
d. I know that he has worked here for ten years.
e. I know that Dad is working in his office at the moment.
f. I know that the Earth goes around the Sun.
2、为一般过去时，除一般的科学规律、自然、永恒的现象”仍然用一般现在时“外，其他情况都受到主句过去时的影响，简而言之，就是把在上面的主句一般现在时的从句中的时态”后移一个时态，如,一般现在时变为一般过去时，现在完成时：过去完成时；现在将来时：过去将来时，等等。
a. I knew (that) he was kind.
b. I knew that he worked in a company.
c. I knew that he would go(= was going) to study in the US next year.
d. I knew that he had worked here for ten years.
e. I knew that Dad was working in his office at the moment.
But we still say,
f. I knew that the Earth goes around the Sun.

建议你了解了相关知识后,适当的做一些练习,通过做练习、思考才能内化知识.下面我就简单介绍一下宾语从句的时态问题 .
1）当主句的谓语动词是一般现在时时,其宾语从句的时态可以是任何适当的时态.所以,宾语从句的时态应根据实际情况而定.eg.
She says (that) she works from Monday to Friday. 她说她从周一至周五上班.
（从句是一般现在时）
She says (that) she will leave a message on his desk. 她说她要在他桌子上留个便条.
（从句是一般将来时）
She says (that) she has never been to Mount Emei. 她说她从来没有去过峨嵋山.
（从句是现在完成时）
2）当主句的谓语动词的时态是一般过去时的时候,其宾语从句的时态一般要用任一适当的过去时态.eg.
He said there were no classes yesterday afternoon. 他说昨天下午没有课.
从句是一般过去时）
He said (that) he was going to take care of the baby. 他说他会去照看这个婴儿.
（从句是过去将来时）
He said (that) they were having a meeting at that time. 他说他们那时正在开会.
（从句是过去进行时）
但是当宾语从句是表达客观真理和规律的句子时,其时态仍旧用一般现在时.eg.
The teacher told us(that) nothing is difficult if we put our hearts into it.
老师告诉我们世上无难事,只怕有心人.
She said(that) her father is twenty-eight years older than her.
她说她父亲比她大二十八岁.
He said that light travels much faster than sound.
他说光比声音传播得快.
He told me that I must go to school on time every day.
他告诉我我必须每天按时上学.
注意：当主句的谓语动词是think或believe,宾语从句要表达否定时,要把从句的否定转移到主句上. eg.
我认为他不会帮你学英语的.
I don't think he is going to help you with your English.
不可以翻译成：
I think he isn't going to help you with your English.
如果宾语从句有它的补语时,宾语从句用it代替,从句后置.其句型为：主语+谓语 + it +补语+宾语从句. eg.
I think it necessary that we learn English grammar.
我认为我们学习英语语法是必要的.
He thinks it a good job that he becomes a teacher.
他认为当老师是个很好的职业.