as用法

　　as可用作連詞，引導(dǎo)比較、時間、原因及方式等四種狀語從句，應(yīng)注意的是，引導(dǎo)的比較狀語從句往往有省略;引導(dǎo)的時間狀語從句一般用一般現(xiàn)在時而不用一般將來時;引導(dǎo)原因狀語從句時與“Because”和“since”引導(dǎo)的從句比較起起來語氣最弱。

　　as作介詞，意思時“作為”，“以……身份”。例如：He came to China as a tourist five years ago.

　　而表示像…一樣時，like通常作介詞用，而介詞后面通常接名詞，代名詞和動名詞。

　　as in Australia“和在澳大利亞一樣”。

　　as……as

　　AS +adj(原級)+AS

　　AS +adv(原級)+AS

　　as soon as 一……就

　　as soon as possible 盡可能快地

　　as early as possible 盡可能早的

　　as carefully as you can 盡可能認真地

　　as careful as you can 盡可能認真的

　　1。as是連詞，表示“隨著”的意義。lives是life的復(fù)數(shù)，意義是“生活”。

　　2。as是連詞，表示“因為，由于”的意義。wanting是現(xiàn)在分詞，表示主動意義，wanting to buy cars=who want to buy cars。

　　As的用法小結(jié)

　　as可以作連詞、介詞及關(guān)系代詞和副詞。現(xiàn)將其用法小結(jié)如下:

　　(一)、 as作連詞的用法:

　　1.作“在-------期間，當(dāng)----的時候”引導(dǎo)時間狀語從句.注意與when、 while的用法區(qū)別。

　　①下列情形時,只用as, 而不用when或while。

　　1)用于表示同一個人的兩種動作交替進行,指一邊----一邊. 如:

　　The girl sings as she goes to school.

　　He looked behind occasionally as he went forward in the forest.

　　2)表示兩個同步發(fā)生的動作或行?意思是隨著-----的發(fā)展.如:

　　As time went on / by, she became more and more beautiful .

　　As children get older, they become more and more interested in everything.

　　3)表示兩個短暫行為或事情幾乎同時發(fā)生.如:I watched her as she read the book.

　　I thought of it just as you opened your mouth.

　　Just as the flying worm hit her face, she gave a loud cry.

　　4)接在名詞后面表示某一個年齡段時.如:

　　As a young man, he was active in sports.

　　②when作"當(dāng)……的時候"解,可以指較短的(一點)時間,也可指一段時間。如:When I was at college, I could speak several foreign languages. When the clock struck twelve, I had slept for 2hours.

　　③ while常表示一段較長的時間或一個過程,強調(diào)主句謂語動詞與從句謂語動詞同時發(fā)生。如:Work while you work. Play while you play.

　　2. As =Since 作"既然"、"由于"解,引導(dǎo)原因狀語從句,常用來表示已為人們所知或顯而易見的原因或理由。如: As he’s been ill for ages, I will help him.

　　As / Since you're not feeling well, you may stay at home.

　　As he wasn't ready , we went without him.

　　3. As =in the way that作"像"、"按照……的方式"解,引導(dǎo)方式狀語從句。如:

　　Do as I told you.

　　Remember, you must do everything as I do.

　　4. 用于as--- as或not / so/ as ---- as中,前一個as是副詞,后一個as是連詞,引導(dǎo)比較狀語從句。如:They helped the old as much as possible.

　　I don't speak English so/ as well as she does.

　　5. 表示雖然,盡管 等,引導(dǎo)讓步狀語從句,常用倒裝語序,模式為:

　　adj. /adv. / n.+as +主語+謂語+主句。如: Young as he is, he knows much.

　　Tired as they were, they walked on.

　　6. 表示也------一樣。 She is a doctor, as was her husband.

　　(二)、 as作關(guān)系代詞,引導(dǎo)定語從句,表示正如,這一點.如:

　　He is very careful, as we all know.

　　As is well-known, Taiwan belongs to China.

　　另外,當(dāng)先行詞被the same, such等詞修飾時,常用as來引導(dǎo)定語從句。如:

　　Such a clever girl as she can learn anything quickly.

　　I was reading the same book as he bought yesterday.

　　(三)、as作介詞的用法.

　　1.表示好像。如:He dressed as a policeman.

　　2. 表示作為當(dāng)作。如：I found a job as a guide.

　　3. 當(dāng)某人是某身份時。如：As a child , she was sent to abroad.

　　4. as引導(dǎo)的介詞短語大多用作狀語,as譯為"作為";少數(shù)情況可引起賓語補足語。如:

　　As a Party member, I'll take the lead in everything. (狀語)

　　She works as a model. (狀語)

　　She has me as one of her best friends.(引起賓語補足語)

　　(四)、作副詞的用法 1 表示與------等同。如：This dress is twice as expensive as that one. 2 像，如等。如：As before, he remained unmoved.

　　總之，通過以上的分析，我們對as的詞性和用法有了比較全面的理解和把握，才能在實際的運用中做到心中有數(shù)，應(yīng)付裕如。