作定語的不定式如果是不及物動詞,或者不定式所修飾的名詞或代詞是不定式動作的地點、工具等,不定式后面須有相應的介詞。例如：He is looking for a room to live in.
There is nothing to worry about.
Please give me a knife to cut with.
There / It is no use/ good/ not any use/ good/ useless doing sth.
動詞后可以用動名詞作賓語,但不能用不定式:
admit,appreciate, avoid, consider, delay, enjoy, escape, excuse, feel like, finish, forgive, give up, imagine, include, keep, mention,mind,miss,practise, put off, resist, risk, suggest, can't help, can't stand(無法忍受)等。
I tried not to go there.(我設法不去那里。)
I tried doing it again.(我試著又干了一次。)]
mean to do 有意... mean doing意味著...
I mean to come early today.(我打算今天早些來。)
Missing the train means waiting for another hour.
(誤了這趟火車意味著再等一個小時。)
allow, advise, forbid, permit
We don't allow smoking here. We don't allow students to smoke.
動詞need,require,want作“需要”解,其后跟動詞作它的賓語時,若表示的含義是被動的,必須用動名詞,或不定式的被動式。例如：
The window needs(requires, wants)cleaning(to be cleaned).
在短語devote to, look forward to, pay attention to, stick to, be used to, object to,thank you for, excuse me for 等后的動詞也必須用動名詞形式：I look forward to hearing from you soon.
Badly polluted, the water cannot be drunk.(原因)
Being written in haste, the composition is full of mistakes.
(原因,強調寫的過程,故應用現在分詞一般被動式)
Having been deserted by his guide, he couldn't find his way through the jungle.(為了強調已完成的動作)
Asked to stay, I couldn't very well refuse.
這里 asked 可能意味著 having been asked, 也可能意味著when/since I was asked, 但用了 having been asked 就不會有歧義。
下面句中過去分詞表示的時間與謂語動詞所表示的時間相同，所以不能代之以強調先于謂語動詞的現在分詞完成被動式。例如：
Covered with confusion, I left the room.我很窘地離開了房間。
United, we stand; divided, we fall. 團結則存，分裂則亡。
He used to live in London, use(d)n't he /didn't he?
There used to be a cinema here before the war, use(d)n't there /didn't there?
Such things ought not to be allowed, ought they?
He ought to be punished, oughtn't he?
但在正式文體中,用ought we not形式。例如:
We ought to go, ought we not?或We ought to go ,should we not?
含有情態動詞must的句子表示推則,作“想必”解時,疑問部分不可用mustn't。若前句強調對現在情況的推測,疑問部分用aren't(isn't)十主語,例如：You must be tired,aren't you?若陳述部分的must表示“有必要”時,附加疑問句部分則用needn't。例如：You must go home right now, needn't you?
當mustn't 表示禁止時,附加疑問部分一般用must。如：
You mustn't walk on grass, must you?
前句謂語動詞是must have＋過去分詞時,若前句強調對過去情況的推測(一般有過去時間狀語),疑問部分的謂語動詞用didn't＋主語;若前句強調動作的完成,疑問部分的謂語動詞用haven't(hasn't)＋主語, 例如：
He must have met her yesterday, didn't he?
You must have seen the film, haven't you?
陳述句謂語部分出現否定詞綴時(前綴或后綴),疑問部分仍用否定結構。例如:He is unfit for his office, isn't he?
如果陳述部分包含有no, never, hardly, seldom, few, little,nowhere, nothing等否定或半否定詞時,疑問部分用肯定形式。例如：He is hardly 14 years old,is he?
如果陳述部分的主語為everyone,someone,no one等不定代詞,其疑問部分的主語可用he,也可用they。
Everyone knows his job, doesn't he?
Everyone knows their job,don't they?
No one was hurt,were they?
I'm late, aren't I?
One can't be too careful,can one(you)?
Have a cup of tea, will you?
Let's go there,shall we? Let us go there,will you?
同位語從句跟在名詞后面,進一步說明該名詞的具體內容。引導同位語從句的名詞主要有fact, news, promise, idea, truth等。連接詞用that (不用which)及連接副詞how, when, where, why等。例如：
His delay is due to the fact that the car went wrong halfway.
The news that our team has won the match is true.
She asked the reason why there was a delay.
關聯詞只能用whether不能用if表示“是否”的情況如下:
A)在表語從句和同位語從句中。例如：
The question is whether the film is worth seeing.
The news whether our team has won the match is unknown.
B)在主語從句中,只有用it作形式主語時,whether和if都能引導主語從句,否則,也只能用whether。例如：
Whether we shall attend the meeting hasn't been decided yet.
It hasn't been decided whether(if)we shall attend the meeting.
C)在介詞之后。(介詞往往可以省略)例如：
It all depends (on) whether they will support us.
D)后面直接跟動詞不定式時。
He doesn't know whether to stay or not.
E)后面緊接or not 時。
We didn't know whether or not she was ready.
F)引導讓步狀語從句,只能用whether。
Whether you like it or not, you must do it well.
G)用if會引起歧義時。例如：Please let me know if you like it.
該句有兩個意思：“請告訴我你是否喜歡”。
或“如果你喜歡,請告訴我。”用了whether就可以避免。
在下面幾種情況下必須用“that”引導定語從句：
1)先行詞是不定代詞：all,few,little, much,something,nothing,anything等。All that we have to do is to practise every day.
2)先行詞被序數詞或形容詞最高級所修飾。
The first lesson that I learned will never be forgotten.
3)先行詞被all,any,every, each, few,little,no,some, 等修飾。
I have read all the book (that) you gave me.
4)先行詞被 the only, the very, the same, the last 修飾時。
He is the only person that I want to talk to.
5)先行詞既有人又有物時。They talked of things and persons that they remembered in the school.
先行詞是表示地點時,要根據從句的謂語動詞是及物的還是不及物的。如果是及物的就用that(which),否則用where。
This is the house where he lived last year.
This is the house that (which) he visited last year.
用no sooner…than和hardly…when引導的從句表示“剛……就……”。主句中的動詞一般用過去完成時,從句用過去時;而且主句一般倒裝,把助動詞had提到前面。例如：Hardly had I entered the room when I heard a loud noise.
代詞作主語時,主謂語序不變。Here it is. Here he comes.
當句首狀語為表示地點的介詞詞組時也常常引起全部倒裝。
South of the city lies a big steel factory.
From the valley came a frightening sound.
表語置于句首時,倒裝結構為“表語+連系動詞+主語”。
Present at the meeting were Professor White,Professor Smith and many other guests.
Gone are the days when they could do what they liked to the Chinese people.
Among the goods are Christmas trees, flowers, candles and toys.
He has been to Beijing. So have I.
Li Wei can't answer the question. Neither can I.
部分倒裝
用于省略if的虛擬條件狀語從句。Had you reviewed your lessons,you might have passed the examination.
3.用于“形容詞(或名詞、動詞)+as(though)引導的讓步狀語從句中。例如：Pretty as she is ,she is not clever.
Try as he would, he might fail again.
如果從句的表語是名詞,其名詞前不加任何冠詞。
Child as he was, he had to make a living.
用于no sooner…than…,hardly…when和not until的句型中。Not until the teacher came did he finish his homework.
用于never,hardly,seldom,scarcely, barely, little,often,at no time,not only,not once等詞開頭的句子。
Never shall I do this again.
Little did he know who the woman was.
6.用于以only開頭的句子(only修飾副詞,介詞短語或狀語從句時)。Only this afternoon did I finish the novel.
Only in this way can you master English.
Only when he told me did I realize what trouble he was in.
如果only后面的詞組不是狀語,則不用倒裝。
Only Wang Ling knows this.
用于某些表示祝愿的句子。May you succeed!祝你成功!
stomach－stomachs，a German－three Germans,
an American－two Americans，man cook - men cooks;
papers 報紙, 文件 manners禮貌 drinks飲料
in a word 簡言之in other words 換句話說
have words with 與某人吵嘴
have a few words (a word) with sb.與某人說幾句話
The crowd were running for their lives．
某些集體名詞, 如people, police, cattle等, 只當復數看待, 謂語動詞必須用復數。The police are searching for him