英语写作中什么时候用非谓语动词开头，举例说说！谢谢

非谓语动词有四种形式， to do , doing ,do, done.
to do 放开头，两种情况：一种是to do 做主语。To study hard is the duty of a students.
一种是做状语，表目的To study hard, he stays up very late.
doing 放开头，也是两种：做主语。Eating healthy food is good for us.
做状语，表伴随状况。Singing and dancing, all the children had a good time.
do 放开头， 一般是祈使句，不过不能算是非谓语形式了。是谓语动词的原形。
done放开头，一般都是状语。Hurt badly, the dog ran away sadly.

语写作中什么时候用非谓语动词开头，举例说说！谢谢

非谓语动词开头有以下几种

（1）Personally-speaking ; Generally-speaking ;

(2) In order to study English well , We must study hard

(3) To learn English well is of great importance

(4) Given more time , He will do this job much better

(5) unless invited , He won't go to attend this meeting

(6) Watching TV is his hobby

(7) Laughing and talking , these students walked out of the classroom