主语从句后置!
为了避免主语冗长,句子头重脚轻,经常用it作 形式主语,主语从句放在后面作真正的主be late is certain. -- It’s certain that we shall be late.
1. That the earth is round is known to all.
Correct or not?
10
*That she wants to know is when the party
will be held .
×
What she wants to know is…….
Pay attention:此主语从句缺少成分-宾语， 故用作成分的what来引导，而不用that。
It is a fact that……
事实是……
It + 不及物动词 ＋ that从句
It appears that…
似乎…
It happens that ….
碰巧…
It occurred to me that…… 我突然想起……
*__It_i_s_a__p_it_y_t_h_a_t__(很遗憾)we lost the match.
What seems easy to some people seems difficult to others. Which side will win is not clear.
3)连接副词when，where， how， why等
Why he did it remains a mystery. When they will start is not known yet. How he became a great scientist is known to us all.
*_I_t_i_s_a_f_a_c_t_t_h_a_t _(这是事实)he cheated in the exam.
*_I_t_i_s_p_o_s_s_ib_l_e_t_h_a_t__(很可能)she will come back tomorrow. *_I_t_i_s_o_b_v_io_u__s_th__a_t __(很明显)this measure is effective.
名词性从句的作用相当于名词，因此主语从句、 表语从句 、宾语从句和同位语从句分别作主句 的主语、表语、宾语和同位语。
Who will win the match is still unknown.
主语从句
I want to know what he has told you.
宾语从句
The fact is that we have lost the game.
-- It’s known to all that the earth is round. 2. That you missed the chance is a pity.
-- It is a pity that you missed the chance.
用it形式主语的that从句有以下四种 不同的搭配：
It + be + 形容词 ＋ that从句
It is necessary that… 有必要… It is important that …. 重要的是… It is obvious that…… 很明显……
It + be + -ed分词 ＋ that从句
It is believed that…
人们相信…
10
*It is important that we will finish the work
on time.
×
It is important that we should finish…..
Pay attention:注意虚拟语气在名词性从句中的
使用！在It is necessary \important \natural\... that…句型中，从句的谓语要用should+do 的形式
表语从句
The news that we won the game is exciting.
同位语从句
主语从句
在句中充当主语的从句叫做主语从句。
1.连接词：
1）从属连词：that， whether等. that 引导主语从句只起引导作用，本身 无实际意义，在主语从句中不充当任何 成分，但不能省略。
It is known to us/all that …. 众所周知…
It has been decided that…… 已经决定……
It + be + 名词 ＋ that从句
It is common knowledge that… …是常识
It is a surprise that …. 令人惊奇的是…
1.___ he made an important speech at
the meeting was true.
A. That B. Why C. What D. How
2. ___we’ll go camping tomorrow depends on the weather .
A If
B Whether
3.That is certain that we can win. It is
4.No matter who leaves the room last ought to turn off the lights. Whoever
5.If the policemen will come is not certain. Whether
C That
D Where
3. It worried her a bit ___ her hair was turning gray.
A.whether
B. that
C. what
D. when
4.What I say and think ___ none of your business.
A. is B. are C. has D have
4. 主语从句需注意的问题 注 意：
1.“if” 不能引导主语从句，应有“whether”引 导2.主。语从句中用陈述语序 3.主语从句的 “that” 一般不能省。
4.“what”引导主语从句时，谓语动词： 1）常与其后的名词作表语一致 2）根据句子的语 境而定。
1.What you left are only several old books.
Correct or not?
10
*When the meeting will be held haven’t been
known yet.
×
……………………………. be held hasn’t been known yet. Pay attention:主语从句的谓语用单数形式
Correct or not?
2.What you said is of great importance.
3.Whether he’ll come here is not clear.
改错练习
1.Where shall we spend the holiday isn’t decided. we shall
2.You have made a mistake is a fact. That you have
That she left him cut him to the heart.
That he will come is certain.
由whether及其他连词引导的主语从句 放在句首，句后都可。
Whether it will please them is not easy to say.
2)连接代词who ，what ，which, whatever, whichever, whoever