宾语从句的时态受主句的限制，
既：主句是一般现在时态，从句根据作文-地带提供实际情况而定。
主句是一般过去时态，从句用相应的过去的时态。如果从句的动作发生在主句之前，则从句要用过去完成时态。
例:
1)She says that she is a student.
She said that she was a student.
2)She says that she will fly to Japan in a week.
She said that she would fly to Japan in a week.
3)She says that she has finished her homework already.
She said that she had finished her homework already.
4)She says that she can sing a song in English.
She said that she could sing a song in English.
l如果宾语从句说的是客观真理、自然现象或事实时，这时宾语从句要用一般现在时态。
例：The teacher said that the earth goes round the sun.
He told me that Japan is an island country.
lCould you tell me…是用来征询对方的意见，语气委婉，并不表示过去。
例：Could you tell me when we will visit the Histury Museum?
注意事项：
u由陈述句变成宾语从句时，要注意人称的变化。
例：She said: "I have been to England before."
She said that she had been to England before.
She asked me: "Do you like maths?"
She asked me if I liked maths.
u宾语从句与简单句的交换。
由连接代词和连接副词引导的宾语从句，如果宾语从句的主语和主句的主语是同一个人时，可以用"疑问词+不定式
"做宾语的简单句结构。
例：I don't know what I should do next.
I con't know what to do next.
He didn't know where he would live.
He didn't know where to live.
DO SOME EXERCISES:
1.Can you see________?
A. what he's reading B. what is he reading
C. what does he read D. he reads what
2.Does Jack come from Japan? Do you know?(合并成一个句子)
Do you know_____Jack _____from Japan?
3._What did your son say in the letter?
_He told me that he___ the Disney would the next day
A.will visit B. has visited
C. is going to visit D. would visit
4.He didn't know__________
A.what's the matter B.what the matter is
C. what was the matter D. what the matter was
5.Somebody called you just now,but I didn't know____
A.who were they B. who they were
C. who was it D. who it was
6.I want to know_____
A.what is his name B. what's his name
C. that his name is D. what his name is
7.---Could you tell me ___she is looking for?
---Her cousin,susan.
A.that B.whose C .who D.which
8.---What are you searching the Internet for?
---I'm trying to find out____.
A.What is the difference between SARS and BIRDFLUjoozone.com