一. 直接引语和间接引语
(一)直接引述别人的原话，叫做直接引语；用自己话转述别人的话，叫做间接引语。间接引语一般构成宾语从句。直接引语必须放在引号内，间接引语则不用引号。直接引语改为间接引语时，除将引语部分变成宾语从句外，还必须对直接引语中的人称、时态、指示代词、时间状语、地点状语等进行改变。
1. 时态的变化：直接引语变为间接引语时，通常受转述动词said，
asked等的影响而使用过去化的时态，即把原来的时态向过去推，也就是一般现在时变为一般过去时，现在进行时变为过去进行时，等等。例如：
Tom said to me，“My brother is doing his homework.”
→Tom said to me that his brother was doing his homework.
2. 人称代词、指示代词、时间状语、地点状语等等的变化： 根据意义进行相应的变化，例如：
She asked Jack，“Where have you been？”
→She asked Jack where he had been.
He said，“These books are mine.”
→He said that those books were his.
(二)直接引语改为间接引语时，都使用陈述语序，但是因为原句的句式不同，所以变成间接引语时所用的连词会有所不同。直接引语如果是一般疑问句，用连接词whether或if；如果是特殊疑问句，则用疑问词引导间接引语。转述的动词一般用asked，可以在其后加上一个间接宾语me，him，her，us等。
例如：
She said，“Is your father at home？”
→She asked me if/whether my father was at home.
“What do you do every Sunday？”My friend asked me.
→My friend asked me what I did every Sunday.
直接引语如果是祈使句，改为间接引语时，要将祈使句的动词原形变为带to的不定式，并在不定式的前面根据原句的语气(即请求或命令)加上ask，tell，order等动词，如果祈使句为否定式，则在不定式前加not。其句型为：ask / tell / order someone (not) to do something.
例如：
She said to us，“Please sit down.”
→She asked us to sit down.
He said to him，“Go away！”
→He ordered him to go away.
He said，“Don’t make so much noise，boys.”
→He told the boys not to make so much noise.
二. 各种时态的被动语态
被动语态概述
被动语态的概念：它是动词的一种形式，表示主语与谓语之间的执行或被执行关系。主动语态表示主语是谓语动作的执行者，例如：They saw thelittle boy crying by the river. 被动语态表示主语是谓语动作的承受者，例如：The little boy was seencrying by the river.
被动语态的构成
被动语态的形式是由“助动词be+动词的过去分词”构成。助动词be随着主语的人称、数、时态等的不同而变化。几种常见时态的被动语态形式如下：
1. 一般现在时 am/is/are + 过去分词
例如：Rice is planted in the south of China.
2. 一般过去时 was/were + 过去分词
例如：These trees were planted the year before last.
3. 一般将来时 will/shall + be + 过去分词
例如：A sports meeting will be held next week in our school.
4. 现在进行时 am/is/are + being + 过去分词
例如：Your radio is being repaired now.
5. 过去进行时 was/were + being + 过去分词
When he got there，the problem was being discussed.
6. 现在完成时 have/has + been + 过去分词
His work has been finished.
Has his work been finished？Yes，it has. / No，it hasn’t.
7. 过去完成时 had + been + 过去分词
注意：
1.除了be之外的其它系动词如get，stay等也可以和过去分词构成被动语态。例如：Their questions haven’t got answered.
2. 含有情态动词的谓语变成被动语态使用“情态动词+ be + 过去分词”结构。
例如：More attention should be paid to the old in this country.
This work can’t be done until Mr. Black comes.
3. 含有“be going to”，“be to”等结构的谓语，其被动语态分别用“be going to + be + 过去分词”和“be to+ be + 过去分词”。
例如：The problem is going to be discussed at the next meeting.
All these books are to be taken to the library.
4.被动语态与系表结构的区别：“连系动词+用作表语的过去分词”构成的系表结构，与被动语态的形式完全一样，所以应注意它们的区别。被动语态中的过去分词是动词，多强调动作；系表结构中的过去分词相当于形容词，多强调状态。前者通常可用by引出动作的执行者，而后者则不可以。
例如：The map was changed by someone.(被动结构)
That custom remained unchanged for many centuries.(系表结构)
系表结构中的过去分词通常可被very修饰，被动语态中的过去分词往往要用much修饰。
例如：He was very excited.(系表结构)
He was much excited by her words.(被动结构)
5. 主动形式表被动意义。有些动词的主动形式有被动意味，如 open，read，sell，shut，wash，wear，write等。此时句子的主语一般是物。
例如：These books sell well. 这些书很畅销。
The door won’t shut. 这门关不上。
The clothes wash well. 这些衣服很好洗。