agrammatical

Agrammatical is an adjective describing language that lacks proper grammar or is ill-formed according to the rules of a language. In linguistics, it is used to indicate sentences or phrases that native speakers judge as violating syntactic or morphological conventions. Agrammatical strings are often contrasted with grammatical strings, and judgments of agrammaticality are a focus of studies on grammaticality, acceptability, and language processing. In everyday use, the term “ungrammatical” is more common, while “agrammatical” appears more frequently in technical or clinical contexts.

In clinical linguistics, agrammatism refers to a language impairment typically associated with Broca’s aphasia, characterized by reduced use of function words and inflectional morphology and by telegraphic speech. Examples such as “Want eat cookie” or “He go store” illustrate omissions of grammar rather than a complete loss of vocabulary, reflecting struggles with constructing proper sentences.

Etymology and usage notes: the word derives from Greek a- meaning “without” and grammata meaning “letters” or “grammar.” The term signals deviation from standard grammar rather than mere lexical error. Related concepts include ill-formedness, grammaticality, and well-formedness, as researchers distinguish between grammatical and semantically odd but grammatical utterances.