一、掌握时间和条件状语从句中的时态与主句时态的搭配
(1)时间状语从句
引导时间状语从句的从属连词有when(当……时候)，while(当，在……过程中)，since(自从……以来)，before(在……之前)，after(在……之后)，tell/until(直到……时)，as soon as(一……就)。如果主句为一般将来时，则时间状语从句只能用一般现在时表示将来的意义。
He was reading the newspaper when I came in.当我进来时，他正在读报纸。
Keep an eye on my cat while I am away.我不在时，请照看一下我的猫。
Don’t talk so loud while others are studying.别人学习时不要大声说话。
It has been five years since she went abroad.她出国已有五年了。
He died before his son came back.他在他儿子回来之前就去世了。
I’ll show him around our factory as soon as he arrives.他一到达我就领他参观我们的工厂。
I’ll tell him about it as soon as I see him. 我一见到他就告诉他。
(2) 条件状语从句
引导条件状语从句的从属连词是if(如果)。如果主句是一般将来时，条件状语从句只能用一般现在时。
If you stay at home, I’ll go.如果你呆在家里，我就走。
If we don’t get up early, we won’t catch the train.如果我们不早起，我们就赶不上火车。
二、掌握宾语从句的语序及其时态与主句时态的呼应
(1)宾语从句的语序
宾语从句的语序一律使用陈述语序。尤其是在把两个独立的句子连成一个含有宾语从句的复合句时必须特别注意：
当宾语从句原为陈述句时，用that引导，语序不变。(注意时态的一致)
Tom isn’t a good student. The teacher told us…→
The teacher told us Tom wasn’t a good student.老师告诉我们汤姆不是一个好学生。
He has given up smoking. She said…→
She said he had given up smoking.她说他已经戒烟了。
当宾语从句原为一般疑问句时，用whether或if连接，语序变为陈述语序。
Is Jim a doctor? I wonder…→
I wonder whether Jim is a doctor.我想知道吉姆是否是个医生。
Does she dance well? Can you tell me…→
Can you tell me if she dances well?你能告诉我她舞跳的是否好吗?
当宾语从句原为特殊疑问句时，特殊疑问词即为连接词，语序变为陈述语序。
She asked me where you were going.她问我你去哪里。
She wondered what he wanted to do.她不知道他想干什么。
(2)宾语从句的时态
宾语从句的时态原则上应与主句的时态保持一致。
如果主句是现在时态(包括一般现在时，现在进行时和现在完成时)，宾语从句可以是实际需要的任何时态。
I am wondering whether he has come or not.我不知道他是否已经来了。(现在完成时)
Please tell me when we’ll have the meeting.请告诉我什么时候开会。(一般将来时)
I don’t know who they are talking about.我不知道他们正在谈论谁。(现在进行时)
I have heard the window was broken by John.我已经听说窗户是被约翰打破的。
如果主句是过去的时态(包括一般过去时，过去进行时)，宾语从句必须选用过去的某一时态(即一般过去时，过去将来时，过去进行时或过去完成时等)
He said he would kill her.他说他会杀了她。(过去将来时)
She told us Lucy had returned home.她告诉我们露茜已经回家去了。(过去完成时)
Mary was wondering who could answer the question.
玛丽想知道谁能回答这一问题。(一般过去时)
I didn’t told them where you were having the meeting.
我没有告诉他们你们正在哪儿开会。(过去进行时)
如果宾语从句表示的是科学其理、客观事实或格言警句等，则不管这句是何种时态，从句一律用一般现在时。
Granny told me that the earth moves around the sun.奶奶告诉我地球围绕太阳转。
She said a friend in need is a friend indeed.她说患难朋友才是真正的朋友。