宾语从句
重点：语序和时态呼应
难点：语序和时态呼应；与疑问词+不定式的转化；与状语从句的辨析
一、宾语从句根据引导词的不同可分为三种类型：
1.由that引导的宾语从句.如：
We knew （that）we should learn from each other.
2.由if/whether引导的宾语从句.如：
Please tell me if/whether you have been to America.
3.由who,where,how等连接代词或连接副词引导的宾语从句.如：
Can you tell me how I can get to the nearest post office?
二、
1.引导词
a.如果从句是陈述句,引导词用that（that在口语或非正式文体中常省略）；
b.如果从句是一般疑问句,引导词用if/whether；
c.如果从句是特殊疑问句,引导词用由疑问词转换而来的疑问代词/副词.
2.语序
①陈述句变为宾语从句,语序不变,即仍用陈述语序.如：
He is an honest boy.The teacher said.→The teacher said（that）he was an honest boy.
②一般疑问句和特殊疑问句变为宾语从句,语序变为陈述语序.如：
Does he work hard?I wonder.→I wonder if/whether he works hard.
When did he leave?I don’t know.→I don’t know when he left.
3.时态
①如果主句是现在的时态,从句的时态可根据实际情况而定.如：
I have heard（that）he will come back next week.
②如果主句是过去的某种时态,那么从句的时态一定要用过去的某种时态.如：
He said（that）there were no classes yesterday.
注意：如果宾语从句表述的是客观真理、自然现象等时,不管主句是什么时态,从句都要用一般现在时.如：
He said that light travels much faster than sound.
三、人称的变化和标点的使用
1.从句的主语如果是第一人称,变为宾语从句则与主句的主语一致；如果是第二人称,则与主句的宾语一致；如果是第三人称,不用变化.如：
“May I use your knife?”He asked me.→He asked me if he might use my knife.
“Do you know her telephone number?”He asked me.→He asked me if I know her telephone number.
2.宾语从句的标点均由主句决定.主句是陈述句,用句号；主句是疑问句,用问号.如：
Who will give us a talk?I don’t know.→I don’t know who will give us a talk.
Do you know?Where does he live?→Do you know where he lives?
四、两副面孔
If既能引导条件状语从句,又能引导宾语从句；when既能引导时间状语从句,又能引导宾语从句.因此,遇到它们就要认真分析一下,它们究竟属于“两副面孔”的哪一副.如：
If it rains tomorrow,I won’t come.（时间状语从句）
I don’t know if it will rain tomorrow.（宾语从句）
五、从句的简化
1.当主句谓语动词是find,see,watch,hear等感官动词时,从句常简化为“宾语＋宾补”结构,宾补为不带to的不定式或V-ing形式.如：
She found that the wallet lay/was lying on the ground.→She found the wallet lie/lying on the ground.
2.当主句谓语动词是hope,wish,decide,forget,plan,agree等,且主句主语与从句主语相同时,从句可简化为不定式结构.如：
She agreed that she could help me with my maths.→She agreed to help me with my maths.
3.在连接代词/副词引导的宾语从句中,当从句主语与主句主语或间接宾语一致时,宾语从句可简化为“连接代词/副词＋不定式”结构.如：
Can you tell me how I can get to the station?→Can you tell me how to get to the station?
