uninflected

Uninflected is a linguistic term used to describe words or languages that do not change form to express grammatical categories such as case, number, gender, tense, mood, or aspect. In a strict sense, an uninflected form remains invariant across contexts, while a language described as uninflected tends to rely on word order, particles, or separate words to convey grammatical relations.

The term is often applied in typology to contrast with inflected languages, which modify word forms as a core means of signaling meaning. Analytic or isolating languages are commonly described as uninflected, because they use little or no affixation. Examples frequently cited include Mandarin Chinese, Vietnamese, Thai, Indonesian, and Malay. In these languages, nouns seldom take inflection for number, and verbs generally do not conjugate for tense or aspect; grammatical relations are indicated by particles, prepositions, or sentence structure rather than internal word changes.

In practice, most languages exhibit some degree of inflection or have subcategories of uninflected words. For instance, many languages have adjectives or pronouns that do not change for number or gender, even if other parts of the lexicon do. Thus, uninflected can describe a predominant morphological pattern rather than an absolute property of every word.

The concept is primarily a descriptive tool in linguistic typology and historic grammar. It informs discussions of how languages encode meaning, influence learning and processing, and shape computational approaches to parsing and lemmatization.