一、引導(dǎo)主語從句的連詞主要有：
從屬連詞：that whether
連接代詞：who whoever whom whose what whatever which whichever
連接副詞：when where how why
二、用法
主語從句是在復(fù)合句中充當(dāng)主語的從句，通常放在主句謂語動詞之前或由形式主語it代替，而本身放在句子末尾。
1. It 作形式主語和it引導(dǎo)強調(diào)句的比較
①主語從句常用it作形式主語，一般常用句型為：It is+{名詞/形容詞/過去分詞}+主語從句例如：
It is still a question whether she will come or not.
It is strange that you should like him.
It is still unknown which team will win the match.
另外，還有一些比較多見的結(jié)構(gòu)：
It turned out that……;
It has been proved that……;
It happened/occurred that……;
It is well-known that……等等
②而強調(diào)句則不同，它的結(jié)構(gòu)是：It+be+被強調(diào)部分+that+從句
強調(diào)主語：It is the times that produce their heroes.時勢造英雄
強調(diào)賓語：It is English that Prof.Lin teaches us.
強調(diào)狀語：It was in shanghai that I saw the film.
判斷是否是強調(diào)句有一個方法，就是將that以后的“句子的其余部分”拿出來單獨看，看有沒有缺成分，缺的是什么成分，再把謂語動詞后面that前面的那部分，帶到你認(rèn)為缺成分的地方，如果放進(jìn)去是一句完整的句子了，那就說明是強調(diào)句。
2. 用it 作形式主語的結(jié)構(gòu)
(1) It is +名詞+that從句
It is a fact that … 事實是……
It is an honor that …非常榮幸
It is common knowledge that …是常識
(2) it is +形容詞+that從句
It is natural that… 很自然……
It is strange that… 奇怪的是……
(3) it +不及物動詞+that從句
It seems that… 似乎……
It happened that… 碰巧……
(4) it is+過去分詞+that從句
It is reported that… 據(jù)報道……
It has been proved that… 已證實……
3.主語從句不可位于句首的五種情況
(1) if引導(dǎo)的主語從句不可居于復(fù)合句句首。
(2) It is said , (reported) …結(jié)構(gòu)中的主語從句不可提前。例如：
It is said that President Jingo will visit our school next week.
(3) It happens…, It occurs… 結(jié)構(gòu)中的主語從句不可提前。例如：
It occurred to him that he failed in the examination.
(4) It doesn’t matter how/whether …結(jié)構(gòu)中的主語從句不可提前。例如：
It doesn’t matter whether he is wrong or not..
(5) 含主語從句的復(fù)合句是疑問句時，主語從句不可提前。例如：
Is it likely that it will rain in the evening?
4. What 與that 在引導(dǎo)主語從句時的區(qū)別
What 引導(dǎo)主語從句時在從句中充當(dāng)句子成分，如主語.賓語.表語，而that 則不然。例如：
What you said yesterday is right.
三、賓語從句用以區(qū)分主語從句的幾個特征
1、引導(dǎo)詞：what which whose when whet herif where
2語序：賓語從句必須是用陳述語句。(名詞性從句都是陳述語序)
如：I think that you must work harder.
賓語從句的引導(dǎo)詞、連接詞的區(qū)別、否定轉(zhuǎn)移等現(xiàn)象。
補充：從句的語序永遠(yuǎn)是陳述句。
1. chat vi.&n. 聊天；閑聊
[典例]
1). What were you chatting to him about? 2). I had a long chat with her (about her job).
[重點用法]
chat to/with sb (about sth) = have a chat with sb (about sth) 與某人聊天、閑談……
2. eastward adv. 向東 adj. 向東的；朝東的
[典例]
1). They were traveling eastward(s) to the city which appeared in their dreams. 他們朝著東邊向夢想中的城市進(jìn)發(fā)。
2). The plane flied in an eastward direction. [詞語歸納]
eastward(s) adj./adv. 向東的，向東地 westward(s) adj./adv. 向西的，向西地
southward(s) adj./adv. 向南的，向南地
northward(s) adj./adv. 向北的，向北地
southeastward(s) adj./adv. 向東南的，向東南地
northeastward(s) adj./adv. 向東北的，向東北地
southwestward(s) adj./adv. 向西南的，向西南地
northwestward(s) adj./adv. 向東北的，向東北地
3. surround vt.&vi. 包圍；圍繞 surrounding adj. 周圍的 surroundings (常用pl.)環(huán)境
[典例]
1). Trees surround the pond.
2). The house was surrounded by high walls.
[重點用法]
surround...with... 用……包圍……
be surrounded by/with... 周圍都是……
4. measure vi.&vt. 測量；衡量；判定 n.[c,u] 尺寸；量具；計量單位；措施
[典例]
1). Can you measure accurately with this ruler? 用這把尺子能量得準(zhǔn)嗎?
2). It’ s hard to measure his ability when we haven’ t seen his work. 沒有見過他的作品, 很難估計他的能力。
[重點用法]
measure A by B 用B衡量A sth. measures 2 metres by 4 metres 某物長4米寬2米
measure sb. for a suit = make a suit to sb’ s measure 給某人量身做一套衣服
5. mix vt.&vi. 混合；調(diào)配 mixture n.[u,c] 混合（物）；混合狀態(tài)
[典例]
1). The chemist mixed (up) some medicine for me.
2). Oil and water don’ t mix.
3). Oil won’ t mix with water.
[詞語歸納]
mix的短語：
mix A and/with B 把甲與乙拌和起來 mix sth. up 把某物拌和；混淆某物
mix sth. in/into把某物摻進(jìn)去 be/get mixed up with sth./sb. 與某事有關(guān)；與某人混在一起
6. nearby adj.附近的；鄰近的 adv.在附近
[典例]
1). Her mother lived in a nearby town. 2). Her mother lived nearby.
[重點用法]
nearby作形容詞時，既可放在被修飾詞之后也可放在被修飾詞之前。
如： There were complaints from nearby residents / residents nearby.
7. terrify vt.使恐怖；恐嚇 terrified adj.恐懼的；受驚嚇的 terrifying adj.（令人）可怕的
[典例]
1). He terrified his children with ghost stories.
2). Her husband’ s violence terrified her. 她丈夫的暴力使她感到恐懼。
[重點用法]
be terrified at/by sth. 被某事（物）恐嚇 be terrified of sth. = be afraid of 害怕某事（物）
8. impress vt.使印象深刻；使銘記 impression n.[c]印象；感想 impressive adj.給人印象深刻的
[典例]
1). The sights of the city never fail to impress foreign tourists. 外國游客無一不對該市留有深刻印象。
2). We were most impressed with/by your efficiency. 你的工作效率很高，我們極為欽佩。
[重點用法]
impress sth. on/upon sb. = impress sb. with/by sth. 使某人銘記某事物
make/give/crate an impression on/upon... 給……一個印象
have/get the impression that 有……的印象
