let sb doing sth

Let sb(do/doing)sth let sb doing sth与have let sb doing sth的区别 let's sb to do sth还是doing sth make /have/ let +sb +do sth.可不可以+do / doing 为什么make /have/ let +sb +do sth.不可以 doing ... sb was doing sth see sb.doing sth. sb in doing sth help sb doing sth have sb doing sth suggest sb doing sth sb spend + doing sth