as 用法歸納總結

　　下面是小編整理的一些關于as 用法總結， 希望讓大家更好地認識as這個單詞，提高英語水平。

　　(一)、As =Since 作"既然"、"由于"解,引導原因狀語從句,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

　　2. .as作連詞的用法:

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

　?、傧铝星樾螘r,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 theforest.

　　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 moreinterested 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 loudcry.

　　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……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 foreignlanguages. 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.

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

　　(二)、 as作關系代詞,引導定語從句,表示正如,這一點.如:

　　He is very careful, as we all know.

　　As is well-known,Taiwanbelongs toChina.

　　另外,當先行詞被the same, such等詞修飾時,常用as來引導定語從句。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. 表示作為當作。如：I found a job as a guide.

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

　　4. as引導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)、as作副詞的用法

　　1 表示與------等同。如：This dress istwice 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)，應付裕如。

　　as...as意為“和……一樣”，表示同級的比較。使用時要注意第一個as為副詞，第二個as為連詞。其基本結構為：as+ adj./ adv. +as。例如：

　　(1)This film is as interesting as that one.這部電影和那部電影一樣有趣。

　　(2)Your pen writes as smoothly as mine.你的鋼筆書寫起來和我的一樣流暢。

　　其否定式為not as/so +adj./ adv. +as。例如：

　　This dictionary is not as/so useful as you think.這本字典不如你想象的那樣有用。

　　總結

　　1.as…as結構中，要使用形容詞或副詞的原形。

　　2.as…as結構用于肯定句或否定句，so…as只用于否定句，用來表示“不如……那樣……”。值得注意的是：它表示的內容總是前者不如后者。使用副詞表示“不相等”的句型中，“not as/so…as…”中的not要和助動詞do,does,did等一起放在行為動詞前，來構成否定句

　　3.as…as結構中，若出現(xiàn)名詞，一般將名詞放在as…as中間。若有形容詞作定語修飾單數(shù)可數(shù)名詞，其前的不定冠詞a/an，須放在形容詞之后。

　　4.as…as結構中如出現(xiàn)表示倍數(shù)的詞，應放在as…as結構之前。如：

　　Our school is four times as large as yours.我們的學校比你們的學校要大四倍。

　　5.as…as結構后接具體數(shù)字時，是表示長、短、高、矮、重、輕等的程度，而不是表示兩者的比較。如：

　　Some stones weighas much as fifteen tons.有些石頭重達十五噸。