a speaker's judgement on the well-formedness of a linguistic 'string'--called a grammaticality judgement--is based on whether the sentence is interpreted in accordance with the rules and constraints of the relevant grammar. If the rules and constraints of the particular lect are followed, then the sentence is judged to be grammatical. In contrast, an ungrammatical sentence is one that violates the rules of the given language variety.

Linguists use grammaticality judgements to investigate