nonderivational

Nonderivational, or non-derivational, is an adjective used in linguistics to describe morphological processes and affixes that do not create a new lexical item or alter the base word’s core meaning. Non-derivational forms primarily serve to express grammatical information rather than to form new words.

In contrast to derivational morphology, which changes a word’s meaning or part of speech (for example, teach -> teacher, happy -> happiness), non-derivational morphology belongs to inflectional morphology. It marks features such as number, tense, aspect, mood, person, and case without reshaping the word into a new lexical item.

Common examples include English plural -s on nouns (cat -> cats) and past tense -ed on verbs (walked). There can be cross-linguistic variation, and some endings may function ambiguously in different languages. The classification can be language-dependent; what counts as non-derivational in one language may interact with derivational processes in another. Some suffixes can be both inflectional and derivational depending on usage, which complicates purely categorical labels.

The term is most often used in discussions of morphological typology, inflectional paradigms, and linguistic description. It helps researchers distinguish the roles morphemes play in forming word forms without generating new lexical items. Related terms include derivation, inflection, morphology, affix, and word formation.