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。

　　[名师点津]　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 keepwarm.

　　为了保暖他关上了窗户。

　　[名师点津]　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。

　　[即时演练1]

　　(1)选出不定式作目的状语的句子

　　①We must do everything we can to help them.

　　②He left, never to return.

　　③To do a good job, we must have the right tools.

　　④We jumped with joy to hear the news.

　　⑤She was too young to understand all that.

　　⑥She studied very hard to get high grades.

　　⑦Many farmers fertilize their crops in order to make them grow more quickly.

⑧We plant trees every year so as to protect the soil on the hill.