We have got to go back
- Luke Skywalker in Star Wars V
I don't think it is actually present perfect usage but certainly used like that syntactically. It is more like simple present usage. What do you guys think?
"Have got to [verb]" is an expression of present obligation. "Have got" is an auxiliary verb construction. The construction has the same meaning of the simpler and more standard "have to [verb]". In your example, "We have to go back" would have the same meaning.
It is a present perfect structure. It uses the present-tense "has" and the participle "got".
I understand what "a present perfect structure" means. It's a grammatical phrasing with identifiable parts. It is a part of English syntax. I have no idea what "a present perfect usage" might mean.
Certainly, I can express similar semantics using very different grammatical structures:
What I think is that structure and meaning are separate concepts. They are related, and we often use one to help explain the other. If they were identical and indistinguishable, we wouldn't be able to do that.