suffixis

Suffixis is a theoretical term in linguistics describing a class of suffixes that attach to word stems to mark grammatical relations and lexical meaning at the end of a word. Suffixis are bound morphemes that typically appear in sequences and are characteristic of languages with rich suffix inventories, including many agglutinative and fusional languages.

The concept is used to distinguish suffixal morphemes whose primary role is inflection or agreement from those used for derivation, though there is overlap with traditional categories. The term combines “suffix” with the plural-like ending -is to indicate a set of related morphemes rather than a single element. It is not universally standardized and is mainly found in typological and theoretical discussions.

In typology, suffixis often interact with stem modification, vowel harmony, and phonological alternations. They may encode information such as case, number, person, tense, aspect, mood, or derivational semantics, and they can stack in multi-morpheme sequences.

Example: a hypothetical language might attach suffixis -a for present tense and -ko for third-person plural, yielding root-a-ko.

In computational linguistics, recognizing suffixis can aid morphological analysis and grammar induction by clarifying the boundary between inflectional and derivational suffixes. See also inflection, derivation, suffix, morphology. Critics note that the label can be redundant with established terminology and should be used with clear linguistic criteria.