1．连词that，只起连接作用，在从句中不作句子成分，也无词汇意义，在口语中常被省略。 eg。 He knew （that） he should work hard。 2．连词if 、whether，它们起连接作用，在从句中不作句子成分，作“是否”解，在口语中多用if。
eg。 Tom don't know if/whether his grandpa liked the present。 He asked me whether or not I was coming。 一般情况下，if 和whether可以互换，但以下3种情况只能用whether： ①在不定式前：Whether to go there or not hasn't been decided。
②在介词前：It depends on（依靠） whether it is going to rain。 ③与or not连用：They are talking about whether to go there or not。 3．连接代词who, whom, whose, what, which，连接副词when, where, why, how， 它们起连接作用，作句子成分，各有自己的意义。
eg。 The teacher asked the new students which class he was in。 I wonder where he got so much money。 【注意】 1．由连接代、副词引导的宾语从句可以和“疑问词+不定式”结构转化。
eg。 I don't know how I should do with the presents。 ==> I don't know how to do with the presents。 2．要注意区分判断由if、when引导的从句类型。
二、宾语从句的语序 宾语从句的语序是陈述语序，即“连接词+主语+谓语+其它成分”。特别强调：它的主语和谓语的语序是陈述语序，而不是疑问句的倒装结构。 Can you tell me who（m） do we have to see?（╳） Can you tell me who（m） we have to see?（ √） The teacher asked the students what they were doing。
（思考: what在从句中的成分） 陈述句变为宾语从句时,要注意人称和时态的变化,语序不变。 eg。 She said, “I will leave a message on the desk。” → She said she would leave a message on the desk。
一般疑问句和特殊疑问句变为宾语从句时,也要注意人称和时态的变化,后面接陈述语序。Eg。 “Where are the tickets?” I asked him。 → I asked him where the tickets are。 三、宾语从句的时态呼应 宾语从句中谓语动词的时态，常常受到主句谓语时态的制约，此为时态呼应。
如果主句谓语是一般现在时或将来时，从句谓语的时态不受限制；如果主句谓语的时态是一般过去时，从句一般要随着改为相应的过去时态（一般过去时、过去进行时、过去将来时、过去完成时）。 eg。 I thought （that） you are free today。
（╳） I thought （that） you would be free today。 （ √） 【注意】当宾语从句叙述的是客观真理时，不管主句谓语的时态如何，从句都用一般现在时。 eg。 The teacher told us （that） the earth moves around the sun。
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宾语从句：是做动词、介词或形容词宾语的从句。 一、做动词的宾语： I think (that) you will like the pictures。 我想你会喜欢这些画的。 （连接词that无意义，在从句中不充当任何成分，可以省略） 当宾语从句（通常是由that引导的宾语从句）有一宾语补足语时，常用it作形式宾语，而将宾语从句置于句末。
例如： I feel it important that they finish their own task in time。 （我觉得他们按时完成自己的任务是很重要的。） 二、做介词宾语： They are worrying about whether they can get there in time。
You can write about whatever topic you can think of。 三、做形容词宾语： Are you sure what you will do next? I'm afraid that he will fail in the exam。
表语从句 表语从句：表语从句置于连系动词后面做表语。例如： The question is whether the book is worth reading at all。（问题是这本书是否有点读的价值。
） That is why we don't like it。 It seems that all of the students have done their homework。 My idea is that we should all do our best。
This is where we found the strange trees。 It seems that everybody agrees to the decision。 同位从句 同位从句一般跟在某些名词如answer(答案)，hope(希望)，fact(事实)，belief (信仰)，news(消息)，idea(主意；观念)，promise(承诺)，information(信息)，conclusion(结论)，order(命令)， suggestion(建议)，problem(问题)，thought (想法)等后面。
例如： He always works hard even if he knows the fact that he is not in good health。 His failure was due to the fact that he had not practised for a long time。
I had no idea that you were here。 She told us her hope that she would become a pianist。 He made a promise that he would never come late。
注意： that 既可引导同位语从句又可引导定语从句，其区别在于：同位语从句由连接词that引导，连接词that本身无意义，在同位语从句中不充当任何成分，不可省略，不可以用其他词替代；定语从句由关系代词that引导，关系代词that在从句中充当一定的成分，作宾语时可省略，由when, why, where引导的 同位语从句和定语从句的区别在于： 同位语从句由连接副词只起连接作用，没有指代作用； 定语从句由关系副词引导，关系副词具有指代先行词的作用，常用一个介词加关系代词替换。
例如:I will never forget the day when we first met。 （同位语从句, when为连接词） That is the special day (which/that) I will never forget。
（定语从句，which/that为关系副词） This is the house where we lived fifteen years ago。 （同位语从句, where为连接词） This is the house which we sold fifteen years ago。
（定语从句，where为关系副词） 。
答：我觉得没有那么麻烦,很简单:动词+引导词(也就是说动词后面紧跟引导词)的句子就是宾语从句了详情>>
答：瑞思用的是美国小学的课程，这一点应该是他们立足市场的关键吧？详情>>
