Question

ing作状语什么时候加逗号

Answer 1

动词-ing作状语时，可以表示原因、让步、时间、条件、方式、伴随和结果等，都可以用逗号隔开，方式也可以不加逗号。
Being ill, he lay down on his bed. (原因状语）
Arriving at home, she began to do housework.( 时间状语)
Working hard, you will succeed sooner or later. (条件状语）
Being a child, he knew more than others. (让步状语）
He got the first prize, making his parents glad.(结果状语）
Traveling by bike, he visited many places in China.(方式状语）
= He visited many places in China （by) raveling by bike,
He came in，holding a book in his hand.(伴随状语）