内容正文:
语法专项知识清单:名词性从句
一、概念与分类
在复合句中具有名词作用,并做主语,表语,宾语和同位语的从句叫名词性从句(Noun Clauses )。分为_______从句、_______从句、_______从句、_______从句。
注意的问题:
1. 引导词
从属连词:that / whether /if / as if (though) ...
连接代词:who / what / which / who / whose/whoever...
连接副词:when / where / why / how/whenever...
2. 语序(陈述语序)
3. 特殊情况(时态、语气等)
二、主语从句
在复合句中做主语的从句叫主语从句。
Eg.①That the earth is round is known to all.
② Whether they will go to Beijing hasn’t been decided.
(一)引导词和语序
1、从句为陈述句,用that引导, 位于句首引导主语从句,不承担句子成分,无实义,但不可省略。
Eg.,Miss White will come to the party.
→_________________________________ has excited all of us.怀特老师会来参加派对,这让我们都很兴奋。
2.从句为一般疑问句,用whether/ if。Whether 引导主语从句可句首、可句中,不承担句子成分,作“是否”义,不可省略,后可接or not。if 作“是否”义,引导主语从句,不可位于句首,后不可接or not.
Eg.Will Miss White come to the party?
→_________________________________ isn’t clear.
=It isn’t clear whether/ if Miss White will come to the party. (句中可用if表“是否”)
注意:从句中要用陈述语序。
3.从句为特殊疑问句,引导词:连接代词/副词,语序:陈述语序。
Eg.① _________ comes is welcome. 不论谁来都欢迎。
②________ this happened is not clear to anyone. 这件事如何发生的没人清楚。
(2) 注意的问题
1.主谓一致: 单个从句作主语,主句谓语动词用三单
①That we find enough water___(be) very important at present.
②When they are leaving for Beijing _____(have) not been decided.
特殊情况:
what引导的主语从句,且what在从句中做宾语时,主句谓语由主句后面的表语/宾语决定。
①What he needs_______time.(be)
②What he needs _______books.(be)
2.it作形式主语句型:that从句作主语时,常用it作形式主语,that引导真正的主语从句后置
(1) It is + adj. + that 从句(necessary必要的/certain明确的/important重要的 /clear清晰的/unlikely不可能的/possible可能的 ……)
eg.It is certain that she will do well in the exam.他一定会考好。
(2)It is + 名词. + that 从句(a pity 遗憾/a shame 遗憾/good news 好消息/a fact 事实 /no wonder 难怪/ no surprise不奇怪)
eg.It is a pity that you didn't attend the lecture yesterday.你昨天没参加讲座真是遗憾。
(3)It is + 过去分词. + that 从句(said 据说/ ordered 根据命令/advised ,suggested建议/thought 认为 /well-known 很著名)
It is generally considered that boys are better at science than girls.人们普遍认为男孩比女孩更擅长理科。
注意:"It +be+ suggested/advised/ordered/requested/ demanded/insisted+that从句”结构中,that从句中谓语应用“should +动词原形”,should可省略。
Eg.It