关于英语的问题为什么by后的动词要用v-ing形式?

Question

关于英语的问题
为什么by后的动词要用v-ing形式?

Answer 1

by doing sth可以理解为：通过...方法
例如：
They learn English by watching TV.他们通过看电视学英语.
He succeeded by working hard.他由于工作努力而获得了成功.
—How do you study for a test?
—I study by working with a group.
I go to school by taking bus.
He finished his homework by asking his sister for help.
I escaped from washing clothes by taking them back home.
He earned enough money for the travelling by working after school.