1．动词,意思是”有”
e.g.He has two cats.Does he have two cats?He doesm't have two cats.
2．助词(与动词的过去分词连用构成完成时）
e.g.They have been in China for three years.
Have they been in CHina for three years?
They haven't been in CHina for three years.
是实意动词