Section Ⅳ Discovering Useful Structures——不定式(短语)作目的状语一、不定式(短语)作目的状语不定式(短语)作目的状语,主要用来修饰动词,表示某一动作或状态的目的。1.to do...为了……这种形式可置于句首(起强调作用,有逗号与句子隔开)或句尾(通常不用逗号隔开)。在句首时常译为“为了……”;在句尾时常译作“以便……,目的是……”。To catch the early bus,I got up early this morning.为了赶上早班车,我今天早上很早就起床了。We work hard to be admitted to a key university.我们努力学习,目的是考上重点大学。[名师提醒] 不定式(短语)表示的是主语的目的,因此其逻辑主语通常是句子的主语。[译]为了画好地图,你需要一支特殊的钢笔。[误]To draw maps properly,a special pen is needed.[正]To draw maps properly,you need a special pen.2.in order to do...为了……这种形式更能突出目的性,既可以置于句首又可以置于句尾。In order to lose weight,he takes exercise like crazy.=He takes exercise like crazy in order to lose weight.为了减肥,他拼命锻炼。3.so as to do...为了……这种形式与 in order to do...一样突出目的性,但 so as to do...不能置于句首。He closed the window so as to keep warm.为了保暖他关上了窗户。[名师提醒] 不定式的否定式均是在 to 前加 not。We had better hurry up in order/so as not to be late for class.为了不上课迟到,我们最好快点。4.不定式的复合结构作目的状语当不定式(短语)有自己的执行者时,需用不定式的复合结构 for sb to do 作状语。He opened the door for the children to come in.他打开门以便孩子们进来。5.目的状语从句与不定式的转换不定式(短语)作目的状语可以与目的状语从句相互转换。(1)当目的状语从句中的主语与主句中的主语相同时,可以直接简化为不定式或不定式短语作状语。例如:We dressed up in order that/so that we could start early.=We dressed up in order to/so as to start early.我们穿戴整齐以便早点动身。(2)当目的状语从句中的主语与主句中的主语不相同时,要用动词不定式的复合结构作状语。I came early in order that you might read my report before the meeting.=I...