写出动词的ing形式用英语怎么说

动词的-ing形式叫做现在分词（present participle）。它由动词原形加上-ing构成，如果动词原形以不发音的字母e结尾，则去掉e再加-ing。例如：

swim → swimming
write → writing
run → running

现在分词一般用来表示正在进行的动作，常和助动词be或动词的进行时连用。
例如：

The boy is swimming in the pool. (男孩正在游泳)
She is writing a letter. (她正在写信)
They are running in the park. (他们正在公园里跑步)

现在分词还可以用来表示被动语态，常和助动词being连用。
例如：

The car being repaired is mine. (正在被修理的车是我的)
The cake being made looks delicious. (正在被做的蛋糕看起来很好吃)

现在分词还可以用来表示目的状语或结果状语。
例如：

He was walking to school. (他走路去上学)
They are waiting for the bus, watching the cars passing by. (他们在等公交车, 看着车经过)