Grammar is a branch of linguistics that studies the structure and rules governing the use of language. It is concerned with the syntax, morphology, and semantics of languages, as well as the relationships between words in a sentence. Grammar research aims to understand how languages are structured and how they are used to convey meaning. Researchers in this field may study language universals, language acquisition, language variation, and language change, among other topics. Ultimately, the goal of grammar research is to gain insights into the nature of human language and communication.