宾语从句定义：宾语从句是指在一个句子中充当宾语的句子女口：He said that he wan ted to be a teacher whe n he grew up.二. 宾语从句有三种类型：1. 由从属连词that引导的宾语从句表示陈述意义，连词that常可被省略。
例如：I hope （that） they will have fun. Mary said that she felt sleepy.2•由从属连词if或whether引导的宾语从句表示是否（有，能，已经••…）” 等一般疑问句的含义。
例如：I wonder whether （if） he lives here.3.由连接代词who,whom,whose,what,which 禾口连接畐U词when,where,how,why 等引导的宾语从句表示谁，谁的，什么，哪（个，些），何时，何地，怎样，为什么”等等特殊疑问句的意义。
除了连接词及被修饰的词提前以外，宾语从句用陈述句语序。
例如：To masked who could give the message to her mother.Do you know what he said just now? I won dered how old his brother was.三. 宾语从句的时态呼应：主现则从任，主过则从过，客观真理一般现”1. 当主句是现在时或将来时的时候，宾语从句可以用所需要的任何时态。
2. 主句是过去时，宾语从句一般只能用过去时的某种形式；当从句叙述的是客观事实或一般真理时，宾语从句仍然用现在时态。
3. 情态动词must —般不用于过去时，但却可以用于主句是过去时的宾语从句中。
四. 宾语从句的语序1宾语从句的连接词后加陈述语序（主语在前，谓语在后）当连接词本身又是宾语从句的主语时，后面直接加谓语动词女口：She asked me who had helped him状语从句英语中，修饰动词、形容词、副词等的句子成分叫状语。
状语的功用：状语说明地点、时间、原因、目的、结果、条件、方向、程度、方式和伴随状况等，根据状语的功能状语从句可分为：时间状语从句、原因状语从句、目的状语从句、结果状语从句、条件状语从句。
时间状语从句：在一个句子中作时间状语的句子。
时间状语的连接词：when （当…时候）while （当…时候）as （当…时候）after （在…以后）before （在…以前）as soon as（—…就）since （自从…到现在）till /until （直到…才）by the time （到…为止）依旧是连接词后加陈述语序。
1. whe n当…的时候（一般情况下：主将从现）2. while 当…时He visited a lot of places while he was traveli ng.3. as 在••的同时；一边••一边…He smiled as he stood up.4. after 在…之后He left the classroom after he had fini shed his homework the other day.5. before 在…之前Mr. Brow n had worked in a bank for a year before he came here.6. as soon as 一…就…一般情况下：主将从现）We bega n to work as soon as we got there.I will write to you as soon as I get home.7. since 自…以来到现在表示自过去的一个起点时间到目前（说话时间）为止的一段持续时间。
主句一般用现在完成时，从句用一般过去时。
Mr Gree n has taught in that school si nee he came to three years ago.还可以用作介词，本句从句还可以用短语：si nee three years ago自三年前以来）表示。
）8 till /un til 直到都可以作连词，连接时间状语，也可以作介词，与其它词构成介词短语，在句中作状语。
They walked till /un til it was dark.Xiao Ming didn ' t leave home till / until his father came back.9. by the time至卜为止（所在句子的主句应用现在或过去完成时）By the time he gets there , his father has already gone.By the time I got to school, the class had already bega n.用法辨析：l.when, while和as的区别When引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。
并且when有时表示就在那时”。
例如：When she came in, I stopped eati ng. 她进来时，我在吃饭。
（瞬时动词）When I lived in the coun tryside, I used to carry some water for him.当的住在农村时，我常常为他担水。
（延续性的动词）We were about to leave whe n he came in. 我们就要离开，就在那时他进来了。
While引导的从句的谓语动作必须是延续性的，并强调主句和从句的动作同时发生（或者相对应）。
并且while有时还可以表示对比。
例如：While my wife was readi ng the n ewspaper, I was watch ing TV.I like playi ng football while you like playi ng basketball 我喜欢踢足球，而你喜欢打篮球。
（对比）As 表示一边•…一边” as引导的动作是延续性的动作，一般用于主句和从句动作同时发生；as也可以强调一先一后。
例如：We always sing as we walk.我们总是边走边唱。
（as表示一边•…… 边”As we was going out, it bega n to snow.当我们出门时，开始下雪了。
（as 强调句中两个动作紧接着先后发生，而不强调开始下雪的特定时间）as when while都表示主、从句动作同时发生，三者差异如下：as表示一边。
一边"的意思whe n1、还可以表示从句动词的动作在主几句动词的动作"之前"或"之后" 发生。
2、w hen = and then; at that moment （正在那个时候）3、常用于常见搭配中while1、用于时间较长时2、强调两个动作同时进行，并表示对比时有时这三个连词可以互换，有时不可以。
It was raining hard whe n （as） I got there.我到那里时，正在下大雨。
（动作同时发生，when可换为as，但不能换为while，因为get是点动词.）When I had read the article, he called me.我看完这篇文章之后，她给我打了电话。
（从句动作发生在主句之前，注意时态表达，只能用when ）When I got to the cin ema, the film had begu n.（当）我到了电影院时，电影已经开演了。
（从句的动作发生在主句之后，只能用when,并要注意时态）He was about to leave, whe n the telepho ne rang.他正要离开，忽然电话响了。
（此时不能放在句首。
主句动词一般表达正在”即将”.while, as不能代替She thought I was talk ing about her daughter, while, in fact, I was talki ng about my daughter.他以为我在谈她女儿，然而，实际上在谈论我女儿。
（表转折，对比，whe n,as都不能代替它）While the alie n was buying a souve nir, the girl called the police.外星人买纪念品时，那女孩给警察打了电话。
（表示主句，从句的动作同时发生，while 后引导的状语从句的动词必须是延续动词不能是点动词，因为它表示较长时间）Mother was worried because little was ill, especially as (whe n/ while) father was away.妈妈担心，因为小爱丽丝病了，特别是他父亲不在家的时候。
(此时as ,when, while可通用)2. 由till或until引导的时间状语从句。
till和until 一般情况下两者可以互换，但是在强调句型中多用until。
并且要注意的是：如果主句中的谓语动词是瞬时动词时，必须用否定形式；如果主句中的谓语动词是延续性动词时，用肯定或否定形式都可以，但表达的意思不同。
例如：I worked un til he came back我工作到他回来为止。
I did n't work un til he came back.他回来我这才开始工作。
3. 由since引导的时间状语从句。
since引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。
一般情况下，从句谓语动词用一般过去时，而主句的谓语动词用现在完成时，表述为：现在完成时+since+一般过去时。
但在It is +时间+ since从句的句型中，主句多用一般现在时。
例如：It is five mon ths since our boss was in Beiji ng我们老板离开北京有五个月了。
知识扩展1. It is …sin从e…以来多长时间了It is five years since we met last time.2. It is …+be fo r e。
…才。
)It was a long time before I went to sleep aga in.It was an hour before(= un til) the police arrived.原因状语从句：在一个句子中作时间状语的句子连接词：由连词because, since, aS引导，也可由for, now that 等词引导1.1 didn ' t go to school yesterday because I was ill.2. Si nee everybody is here, let ' s beg in o 既M eetin g.3. As you are in poor health, you should not stay up late. 既然。