雖然so as to與so...as to在形式上差不多,而且后面都接動詞原形,但它們表示的意思和在句中的作用卻不同:前者表示“為的是; 是為了; 以便”的意思,與其后的動詞原形一起作目的狀語,用來強(qiáng)調(diào)目的; 后者表示“那么地……,以至……”的意思,so后面接形容詞或副詞,在句中as to和其后的動詞原形一起作結(jié)果狀語.例如:
Sometimes my friend goes to the library so as to borrow books.我朋友有時(shí)去圖書館為的是借書.
Tomorrow my father will go to Beijing so as to see his old friend.我父親明天去北京是為了看望他的老朋友.
The girl was so excited as to shout herself hoarse.那個(gè)女孩興奮得喊啞了嗓子.（或譯為:那個(gè)女孩是那么地興奮,以至于嗓子都喊啞了.）
He was so tired as to be unable to walk.（＝He was too tired to walk.）他累得走不動了.（或譯為“他是那么累,以至于不能走路了.）
She is so wise as to solve the problem.她非常聰明,能解決這個(gè)問題.
The little boy ran so fastas to falldown.那個(gè)小男孩跑得太快,跌倒了.（或譯為:那個(gè)小男孩跑得那么地快,以至于跌倒了.）
Yesterday morning I got up so late as to be late for school.昨天早晨我起得那么晚,上學(xué)都遲到了.
另外,還有三點(diǎn)需注意:
1.如果是表示否定目的,則要在“to”前加否定詞not,即要用“so as not to”的形式.例如:
Let''''s hurry up so as notto be late for class.我們快點(diǎn)走吧,以免上課遲到.
Next week I am going to Beijing so as not to attend a meeting.我下星期去北京不是為了開會.
2.so...that 和so...as to雖然表示的意思幾乎是一樣的,而且兩個(gè)so后面都是接形容詞或副詞,但它們所在的句子種類不同:前者所在句子是帶結(jié)果狀語從句的復(fù)合句,而后者所在句子是簡單句.當(dāng)復(fù)合句的主句和從句的主語相同,而且從句又是表示肯定意思時(shí),兩者可互換使用.例如:
Just now they were so happy that they jumped.可改為:Just now they were so happy as to jump.剛才他們高興得跳了起來.
3.in order to是so as to的同義詞組,兩者一般可互換使用.但是,當(dāng)特別強(qiáng)調(diào)目的,且把目的狀語放在句首時(shí),只用in order to.例如:
In order to realize our dreams earlier,each of us must study even harder.為了早日實(shí)現(xiàn)我們的理想,我們每個(gè)人都必須更加努力地學(xué)習(xí).