车来了,为什么是here comes the bus而不是here is coming the bus呢?

为什么是“look ,here comes the bus"而不是"here is coming the bus"明明有 HERE COMES THE BUS=THE BUS IS COMING? here comes the bus /the bus is coming Here comes the bus=The bus is coming还是The bus comes here? Here comes the bus 为什么不是 here is coming the bus here comes the bus 为什么不是the bus comes here? Don't worry.Look!Here comes the bus.为什么这里用comes而不用is coming The bus comes here. look,here comes the bus为什么是comes? Here comes the bus.车来了 为什么用一般现在时啊? come的用法谁能帮我总结一下?Here comes the bus.为什么不是is coming?那I coming有 here is coming the bus 语法上哪里错了?