请问be going to do sth ,其中的成分是什么?be是助动词,going是谓语,to do sth 是go的宾语吗?
be going to常整体地当作助动词,后接动词原形一块构成句子的谓语,也有人称其为“复合谓语”。夸克《英语语法大全》(P.193)将此类结构视为“半助动词”,摘录如下:
半助动词:begoing to等
3.14 半助动词包含一批动词习语,它们具备情态或体的意义,并由动词HAVE或BE引导;比如:
be able to; be bound to; be likely to; be supposed to; be aboutto; be due to; be meant to; be willing to; be apt to; be going to; be obligedto; have to
半助动词范畴的边界不清楚:可以扩大到把be unable to,be unwilling to等否定习语也包含进来。……