To do放在句子中是“为了...”的意思,如:To get to the zoo,you must cross the roadDoing是用作动名词,如:Doing homework is important.Do用在祈使句中,如:Open the door,please.
原型 祈使句 就是有命令的语句Close the door pleaseTo do 表示目的To fininsh the work on time,he studied till 11 pmDoing 作主语除了以上两种情况 就用Watering flower every morning has been one of my habits
to do是动词不定式作主语,doing是动名词作主语(这两个其实时可以互换的,doing是祈使句的时候用
表目的将来用to do .其他时候doing to do 几乎可以调.祈使句用原形