-nen

Etymology
Originally a variant form of. The -i- was dropped in certain dialects, particularly nouns with more than two syllables prior to the suffix. The distinction between using for nouns (including nouns with two or fewer syllables in the root) and  for adjectives is a later literary invention, resulting in these two variants of the same suffix being artificially separated in meaning.

Usage notes

 * Surnames ending in were first recorded in Savonia (and to a somewhat lessex extent Karelia) in the early 16th century, with  affixed to nicknames  and vernacular forms of given names  after the ancestor or patriarch of a family. In the 19th century surnames were required of all Finns, and many new names were created by adding  to topographic terms  and to words describing natural phenomena.
 * 38% of Finns had a surname ending in in 1985.
 * Should not be confused with with which it may be conflated in colloquial speech and some dialects. For example,  may appear to be  +, but is actually a colloquial form of , itself  +.
 * As with, nominals have a combining form that replace the suffix with an , which is used whenever they are followed by another part in a compound word: e.g.  (> ) +  =.

Declension
Back vowel harmony declension (includes vowels a, o, u)

Front vowel harmony declension (includes vowels ä, ö, y)