英語(yǔ)中的動(dòng)詞不定式具有副詞的功能,可以在句子中作狀語(yǔ),表示多種意義.在這里就動(dòng)詞不定式作目的狀語(yǔ)進(jìn)行單獨(dú)討論.
　　一、不定式和不定式短語(yǔ)作目的狀語(yǔ)
　　不定式和不定式短語(yǔ)作目的狀語(yǔ),主要用來修飾動(dòng)詞,表示某一動(dòng)作或狀態(tài)的目的.為了使目的意義更加清楚或表示強(qiáng)調(diào)意義時(shí),還可以在前面加 in order to 或 so as to.例如：
　　I've written it down in order not to forget.
　　He shouted and waved so as to be noticed.
　　在句子中作謂語(yǔ)動(dòng)詞的狀語(yǔ)的不定式或不定式短語(yǔ),表示的是主語(yǔ)的目的,因此,其邏輯主語(yǔ)通常是句子的主語(yǔ).比較：
　　To draw maps properly,you need a special pen.(正)
　　To draw maps properly,a special pen is needed.(誤)
　　由 in order to 引導(dǎo)的目的狀語(yǔ),既可以置于句尾,也可以置于句首,而由 so as to 引導(dǎo)的目的狀語(yǔ),只能置于句尾,而不能置于句首.比較：
　　They started early in order to get there in time.(正)
　　In order to get there in time,they started early.(正)
　　They started early so as to get there in time.(正)
　　So as to get there in time,they started early.(誤)
　　二、不定式的復(fù)合結(jié)構(gòu)作目的狀語(yǔ)
　　當(dāng)不定式或不定式短語(yǔ)有自己的執(zhí)行者時(shí),要用不定式的復(fù)合結(jié)構(gòu)(即在不定式或不定式短語(yǔ)之前加 for + 名詞或賓格代詞)作狀語(yǔ).例如：
　　He opened the door for the children to come in.
　　She fetched several bottles which she placed on the counter for Harry to inspect.
　　三、目的狀語(yǔ)從句與不定式的轉(zhuǎn)換
　　英語(yǔ)中的目的狀語(yǔ)從句,還可以變?yōu)椴欢ㄊ交虿欢ㄊ蕉陶Z(yǔ)作狀語(yǔ),從而使句子在結(jié)構(gòu)上得以簡(jiǎn)化.可分為兩種情況：
　　1.當(dāng)目的狀語(yǔ)從句中的主語(yǔ)與主句中的主語(yǔ)相同時(shí),可以直接簡(jiǎn)化為不定式或不定式短語(yǔ)作狀語(yǔ).例如：
　　We'll start early in order that/so that we may arrive in time.
　　We'll start early in order to/so as to arrive in time.
　　2.當(dāng)目的狀語(yǔ)從句中的主語(yǔ)與主句中的主語(yǔ)不相同時(shí),要用動(dòng)詞不定式的復(fù)合結(jié)構(gòu)作狀語(yǔ).例如：
　　I came early in order that you might read my report before the meeting.
　　I came early (in order) for you to read my report before the meeting.