Konsonanttigraduaatio

Konsonanttigraduaatio is a morphophonological process found in Finnic languages, most notably Finnish, in which stem-internal consonants alternate between two phonological realizations across different inflectional forms. The two realizations are typically described as the strong grade and the weak grade. The alternation concerns the consonant of the stem and is triggered by suffixal contexts rather than by isolated vowel changes; it is a systematic part of the word’s inflectional paradigm rather than a random irregularity.

The exact mapping between grades varies by word, dialect, and part of speech, but the general idea is that the strong grade presents a fuller or more marked consonant realization, while the weak grade shows a shortened, lenited, or otherwise reduced form. The changes are conditioned by morpheme boundaries and by the presence of certain endings, such as plural, case, or possessive suffixes, and may occur in nouns, adjectives, and some verb stems. Not all stems participate in gradation, and there are multiple gradation patterns described in the linguistic literature; some are productive in standard Finnish, while others are primarily observed in dialects.

From a typological perspective, consonant gradation is a central feature of Finnic morphophonology and reflects historical sound changes that have persisted into the modern inflectional system. Researchers classify gradation into several classes based on the consonant segments involved and the specific phonological operations (such as length changes, voicing shifts, or deletions) that produce the different grades. The phenomenon influences spelling–pronunciation correspondences and is learned as part of mastering inflectional paradigms.

See also: Finnish phonology, vowel gradation, Finnic languages.