watch sb do/doing sth 为什么不在do/doing前面加to呢

watch sb do/doing sth 为什么不在do/doing前面加to呢 watch sb do/doing sth;see sb do/doing sth；hear sb do/doing s 紧急】see sb do/doing sth,watch sb do/doing sth,look at sb do/d watch sb.(to) do sth.和watch sb.doing sth.的区别 watch sb doing sth \ watch sb do sth \ see sb doing sth\ see watch sh do sth 还是watch sb doing sth tell sb doing sth还是tell sb to do sth help sb doing sth和help sb to do sth Hear sb to do sth 和 hear sb doing sth help sb in doing sth &help sb to do sth take sb.doing sth.还是take sb.to do sth. ask sb to do sth和ask sb doing sth