English Grammar - Negative Forms of MUST & HAVE TO

For the rules of the English language, see English grammar. For the topic in mathematics, logic, and theoretical computer science, see Formal grammar. In linguistics, grammar is the set of logical and structural rules that govern the composition of sentences, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology and syntax, often complemented by phonetics, phonology, semantics, and pragmatics.