Consonant gradation

Consonant gradation is a type of consonant mutation in which consonants alternate between various "grades". It is typical of Uralic languages such as Finnish, Estonian, Northern Sámi, and the Samoyed language Nganasan. Of the Finnic languages, Votic is known for its extensive set of gradation patterns. Consonant gradation in some of these languages is not (or is no longer) purely phonological although it may be surmised for various reconstructions of Proto-Finnic. In archiphonemic terms, the mutation is a type of lenition in which there are quantitative (such as /kː/ vs. /k/) as well as qualitative (such as /k/ vs. /v/) alternations.