so that的用法

壹、引導目的狀語從句　so that“以便，為了”，引導壹個表示目的的狀語從句，此時可與 in order that 換用；從句謂語中常用情態動詞 may/might, can/could, should, would 等；主從句間連接緊湊，沒有逗號相隔。例：　　My old father began to study computer at the age of sixty so that(= in order that) he might keep up with times. 父親六十歲時才開始學習電腦，以便跟上時代。　　I spend more time learning English every day so that(= in order that) I can make greater progress this year. 為了今年取得更大進步，我每天用了更多的時間學英語。　　二、引導結果狀語從句　　so that“因此，所以”，引導壹個表示結果的狀語從句，此時不能與 in order that 換用；從句中謂語根據需要使用相應的時態，主從句間可有逗號相隔。本文開頭所列舉例句中的 so that 就是這種用法。又如：　　She had not planned her time well,so that she did not finish her homework on time. 她沒把時間計劃好，所以沒按時完成家庭作業。　　Wang Lang did not work hard enough, so that she is out of work when she is still young. 王浪工作不夠努力，因此，年輕時就失業了。　　三、辨別兩種不同狀語從句　　1) 根據句子結構辨別　　從句謂語中含有情態動詞 may/ might,can/ could, should, would 等，這時 so that 引導的是壹個目的狀語從句；從句前面有逗號和主句相隔，此時 so that 引導的是壹個結果狀語從句。試對比以下兩個例句：　　Yesterday morning Yang Cheng got up early so that she could catch the first bus. 昨天早上楊成為了趕上早班車起床很早。　　Yesterday morning Yang Cheng got up early, so that she caught the first bus. 昨天早上楊成起床很早，因此，她趕上了早班車。　　2) 根據主從句邏輯關系辨別　　so that 引導目的狀語從句，壹般表示尚未完成的目的或意圖，主句和從句之間是結果與目的關系；而 so that 引導的結果狀語從句則是表示主句所導致的結果，主句和從句之間是原因與結果的關系。試比較：　　I tell my students my new telephone number so that they may call me when necessary. 我把新的電話號碼告訴學生以便必要時他們給我打個電話。　　I told my students my new telephone number so that all of them called me when necessary. 我把新的電話號碼告訴了學生，因此，必要時他們都給我打了電話。　　四、同其它結構轉換　　so that 引導目的狀語從句時，可以與表目的的動詞不定式 (not) to do …/so as(not)to do …/ in order (not) to do … 互換。但主從句主語須壹致(句 ① ②)，否則不能轉換(句 ③)。　　① We went to the airport so that we might meet Professor Yang there.　→ We went to the airport to meet Professor Yang there.　→ We went to the airport in order to meet Professor Yang there.　→ We went to the airport so as to meet Professor Yang there.　② They had to walk a long way to/ in order to/ so as to fetch some firewood.　→ They had to walk along way so that they might fetch some firewood.　③ Mr.Cheng turned up the recorder so that every student in the classroom could hear clearly. (主從句主語不壹致)