to have
want后加动词不定式，就是I want to have a sweater.我想要一件毛衣。
want to do sth 想做某事want sb.to do sth 想让某人做某事
to have，因为to后面加动词原型，而sweater正好是原型
固定搭配want to do sth. 填to have.
