概念：冠詞是置于名詞前并限定名詞意義的虛詞。英語(yǔ)中的冠詞只有定冠詞和不定冠詞兩種，其中定冠詞只有the這一種形式，不定冠詞只有a和an這兩種形式。名詞前若不用冠詞時(shí)，又稱作零冠詞。不定冠詞之所以冠以“不定”兩字，就是因?yàn)樗闹饕攸c(diǎn)就是“不確定”或“泛指”；定冠詞之所以冠以“定”字，就是因?yàn)樗闹饕攸c(diǎn)是“確指”或“特指”。
1a 與 an 的用法區(qū)別
1.基本區(qū)別：原則上說(shuō)，a用于輔音前；an用于元音前。輔音前用a的例子如:?a book, a student, a school, a house, a magazine?等；元音前用an的例子如:?an egg, an apple, an object, an idea, an ugly thing?等。
2.易錯(cuò)說(shuō)明：hour, honest, honor?等單詞的拼寫(xiě)雖然以輔音字母h開(kāi)頭，但其讀音卻以元音開(kāi)頭，因此，前面要用an。反過(guò)來(lái)，有些單詞雖然以元音字母開(kāi)頭，但其讀音卻以輔音開(kāi)頭，那么它們的前面應(yīng)用a而不是an，這些詞常見(jiàn)的有useful, university, usual, European, united, one-eyed, one-way?等。
此外，對(duì)于數(shù)字、字母以及由單詞首字母構(gòu)成的縮略詞，其前到底是用a還是an，也需根據(jù)讀音來(lái)確定，如下：
He has?an?11-year-old daughter.?
Our daughter sent us?an?SOS for some more money.?
2冠詞在句中的位置
1. 通常位置：一般說(shuō)來(lái)冠詞放在單數(shù)可數(shù)名詞之前(如?a man / the man)，如果名詞有其他定語(yǔ)，不定冠詞應(yīng)放在定語(yǔ)之前(如a good man / the good man)。
2. 特殊位置：在下面情況中，冠詞的位置比較特殊，需要注意。
①?單數(shù)可數(shù)名詞被 ?such, many, half, what?等修飾時(shí)，不定冠詞應(yīng)置于其后，這個(gè)大家看例子就很容易明白，而且平時(shí)基本不會(huì)出錯(cuò)。
He arrived half an hour ago.?
He couldn’t afford to pay such a price.?
② 單數(shù)可數(shù)名詞前作定語(yǔ)的形容詞被?as, so, how, too?修飾時(shí)，通常采用?“as / so / how / too +?形容詞?+ a / an +?名詞”這樣的詞序。
He didn’t know how great a mistake he had made.?
It is too difficult a job for me to finish in so short a time.?
③ 當(dāng)定冠詞與?all, both, half?表倍數(shù)的?double, twice, three times?等分?jǐn)?shù)詞等一起修飾名詞時(shí)，定冠詞應(yīng)放在它們之后。
Turn off?all the lights?before you go to bed.?
Everything was almost?double the normal price.?
3不定冠詞的基本用法
1. 表類別：即指人或事物的類別。
A teacher is a person who teaches.?
2. 表數(shù)量：即表示數(shù)量“一”。
I’ll be able to finish it in a day or two.?
3. 表同一性：即表示“同一”，說(shuō)明事物的同一性質(zhì)、特征、大小或程度等。
This hat and that one are of a shape.?
4. 表程度：用于most前表示“非?！薄笆帧薄?/p>
It’s a most boring book.?
4不定冠詞的考點(diǎn)性用法
1. 用于序數(shù)詞前：表示“再一”、“又一”。
She thanked him a second time.?
Shall I ask her a third time??
2. 用于由動(dòng)詞轉(zhuǎn)化來(lái)的名詞前：表示一次、一番等義(通常與?have, take, make, give?等動(dòng)詞連用)。
We’ve already had a try at it.?
I went down to the beach and took a swim.
3. 用于專有名詞前：相當(dāng)于a certain，意為“一個(gè)”“某個(gè)”。
The house next door has been bought by a Mr Jones.?
4. 用于抽象名詞前：使之具體化，表示與該之相關(guān)的具體的人或事。
He was a success in business.?
It’s a pleasure to talk with you.?
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5定冠詞的基本用法
1. 表示特指：特指某(些)人或某(些)物(包括用于上文提到過(guò)的人或物之前，以及說(shuō)話雙方都知道的人或物)。
We have a cat and two dogs. The cat is black and the dogs are white.?
2.?表示獨(dú)一無(wú)二：用在世界上“獨(dú)一無(wú)二”的事物的名詞前。
The earth goes round the sun.?
He looked up at the stars in the sky.?
3. 用于最高級(jí)前：即用于形容詞或副詞的最高級(jí)前。
Who picked the most apples??
Of the four of us, I sang the worst.?
4. 用于序數(shù)詞或方位詞之前。
He was the first man to think of it.?
Italy?is in the south of Europe.?
5. 用于樂(lè)器名詞前：表示相應(yīng)樂(lè)器的演奏。
Besides the violin, he plays the piano and the flute.?
6. 表示人體部位：用于某些介詞短語(yǔ)中指身體的某個(gè)部位。
He patted me on the back.?
We caught him by the arm.?
7. 用于表示一家人：用于在姓氏的復(fù)數(shù)形式之前表示一家人或夫婦二人。
The Smiths live in the apartment above ours.
8. 用于江河湖海等前：用于江河湖海、山脈群島、海灣海峽等地理名詞前。如：
The Yellow River flows into the Yellow Sea.?
9. 用于某些含有普通名詞的專有名詞前：用于某些國(guó)名、組織機(jī)構(gòu)、建筑物、報(bào)紙雜志、會(huì)議條約等含有普通名詞與其他詞構(gòu)成的專有名詞。
We visited the Great Wall yesterday.?
6定冠詞的考點(diǎn)性用法
1. 用于整十的復(fù)數(shù)數(shù)詞前：表示幾十年代。
This happened in the seventies.?
2. 用于比較級(jí)前：用于“the+比較級(jí)，the+比較級(jí)”結(jié)構(gòu)中表示“越……就越……”。
The sooner we operate now the safer.?
The better I knew him, the more I liked him.?
3. 用于表示類別：用于“the+某些形容詞或過(guò)去分詞”中表示一類人。
Do you think the rich should pay more taxes to help the poor??
The sick and the wounded were sent home.?
4. 用于國(guó)籍名詞前表總稱：用于“the+某些國(guó)籍的形容詞”中表示某國(guó)人的總稱。
The French are famous for their food.?
The British drink a great deal of tea.?
5. 用于集合名詞前表總稱：用于“the + police / public等集合名詞”中表示這類人的總稱。
The police are looking for the murderer.
6. 用于修飾same, only, very等形容詞：即用于“the same / only / very +名詞”結(jié)構(gòu)中。
That’s the only reason.?
Do you belong to the same class??
My view is the very opposite of his.?
7. 用于單位名詞前表示標(biāo)準(zhǔn)：即用于“單位詞”（hour, day, month, year, dozen, gallon, ton, yard等）前表示標(biāo)準(zhǔn)，相當(dāng)于漢語(yǔ)的“按”“論”“每”等。
They let out cars by the day.?
Do you sell eggs by the kilo or by the dozen??
但是，by weight（按重量）習(xí)慣上不用冠詞。
Bananas are usually sold by weight.?
7使用零冠詞的典型情形
所謂用零冠詞，即既不用定冠詞，也不用不定冠詞。這類情況主要有：
1. 表泛指的不可數(shù)名詞或復(fù)數(shù)名詞前。
Snow was failing.?
Children get a better education today than at any time in the past.?
2. 倒裝的讓步狀語(yǔ)從句中：在as(雖然)引導(dǎo)讓步狀語(yǔ)從句前面的單數(shù)可數(shù)名詞前不用冠詞。
Child as he was, he knew how to help others.?
3. 某些特殊詞前：例如在man(人，人類), word(消息)的前面不用冠詞。
Man is a rational animal.?
Word came that he had married again.
又如動(dòng)詞?turn(變成)，go(變成)后作表語(yǔ)的名詞前通常用不用冠詞。
He was a teacher before he turned writer.?
4. 獨(dú)立主格結(jié)構(gòu)中：在表示伴隨或補(bǔ)充說(shuō)明用用的獨(dú)立主格結(jié)構(gòu)中，名詞前不用冠詞。
The teacher came in, book in hand.?
He was sitting in the chair, pipe in mouth.?
5. “(a) kind [sort] of＋名詞”結(jié)構(gòu)的“名詞”前：該結(jié)構(gòu)中的“名詞”不管是單數(shù)還是復(fù)數(shù)，其前都通常用零冠詞。
This kind of book is very interesting.?
He is the sort of person I really dislike.??
6. 表抽象意義的單數(shù)名詞前：當(dāng)單數(shù)可數(shù)名詞含義抽象化具有形容詞意味時(shí)，通常用零冠詞。
I was fool enough to accept his offer.?
Are you man enough for this dangerous job??
