linguistics
theoretical linguistics
https://en.wikipedia.org/wiki/Theoretical_linguistics
https://www.wikidata.org/wiki/Q351625
The branch of linguistics which inquires into the nature of language itself and seeks to answer fundamental questions as to what language is; how it works; how universal grammar (UG) as a domain-specific mental organ operates, if it exists at all; what are its unique properties; how does language relate to other cognitive processes, etc.
general linguistics