he works hard.中work为什么加s?

he works hard.中work为什么加s? He works for an IT company这里的work为什么要加s呀? He works a plower plant.为什么works要加s? he is work hard 和he is works hard 和he works hard有什么区别、、 my father works in a bank work 为什么加s? Success depends on hard work中depend为什么要加s 为什么是he works hard而不是he works hardly? how hard ( A he work B does he work C he works D do he work He works hard .And he is s------of success he works hard She does not work so hard as you.为什么work不加s 英语求教John works for a school.为什么 work 要加s