-inen

From Proto-Finnic *-inën. Originally also had the variant -nen, but in the standard language, the two variants have been made distinct by giving them different uses.

• IPA^(key): /-inen/, [-ine̞n]
• IPA^(key): /-ne(n)/, [-ne̞(n)] (colloquial, dialectal; see usage notes)

-inen

1. Creates adjectives:
   1. Creates adjectives signifying a certain quality: -like, -ous, -y

      ‎vuoristo (“mountain range”) + ‎-inen → ‎vuoristoinen (“mountainous”)

      ‎sotku (“mess”) + ‎-inen → ‎sotkuinen (“messy”)

      ‎talvi (“winter”) + ‎-inen → ‎talvinen (“wintry”)

   2. Creates adjectives indicating a material of which something is made: -en

      ‎kulta (“gold”) + ‎-inen → ‎kultainen (“golden”)

      ‎puu (“tree; wood”) + ‎-inen → ‎puinen (“wooden”)

   3. Creates adjectives from present active participles, indicating a tendency to be/do something.

      ‎taipuva (“flexible”) + ‎-inen → ‎taipuvainen (“inclined, predisposed (to do something)”)

   4. Creates adjectives from foreign roots: -ic

      ‎demokraatti- + ‎-inen → ‎demokraattinen (“democratic”)

      ‎konstruktiivi- + ‎-inen → ‎konstruktiivinen (“constructive”)

• This suffix is highly productive.
• All -inen nominals belong to declension class 38 (nainen). Nominals belonging to this class have special combining forms.
  • The combining form used for most -inen derivatives (including basically all nouns) before other words in a compound: the final -nen is replaced with -s-:

    erikoinen → erikois-     pohjoinen → pohjois-     yhteinen → yhteis-

  • For -inen words where the root is of Latin or Greek origin, the -s- too is often dropped.

    nominaalinen → nominaali-     sosiaalinen → sosiaali-     virtuaalinen → virtuaali-

  • -inen adjectives which derive from other nominals may have combining forms that behave as if the suffix were not present.

    punainen (< puna) → puna-     kertakäyttöinen (< kerta + käyttö) → kertakäyttö-     monitoiminen (< moni + toimi) → monitoimi-

• When appended to verbs ending in -taa, -tää, the verb stem ending in -te- is used.

  kerrostaa → kerrosteinen

• When appended to certain adverb endings ending in -in such as -kkain and -ttain, the combination contracts to -kkainen, -ttainen and so on.
• Should not be confused with the diminutive suffix -nen in the standard language. The two suffixes are however etymologically identical and hence the distinction may not be observed in some dialects.
  • Colloquially and dialectally, -inen may lose its -i-. In the most common variants of colloquial Finnish, the -i- is elided if it is unstressed and immediately preceded by a vowel that is not e and is in the same syllable as -i- (i.e. part of a -Vi- diphthong). The dropping may be avoided if it would result in an unacceptable amount of ambiguity.
• -hinen was originally a distinct suffix, but has become confused with -inen, and most speakers do not recognize them as separate suffixes.
• With foods, the resulting adjective can be translated generally as "containing or resembling ...". For example, an adjective like mansikkainen (← mansikka (“strawberry”)) refers to something that has a prominent strawberry flavor or aroma, usually because strawberry was an ingredient. If the flavor was obtained artificially, or one otherwise wishes to emphasize the flavor, one might want to instead use an adjective such as mansikanmakuinen ~ mansikan makuinen (“strawberry-flavored”). If one wishes to emphasize that something does contain strawberry, especially in technical contexts, one may say mansikkaa sisältävä or mansikkapitoinen.
• When creating adjectives from foreign roots, the root usually takes on the form it would have if it were an independent noun; for example, since "a Democrat" is demokraatti, the resulting adjective is demokraattinen. Some adjectives exhibit free variation between a form that ends in -i and one that ends in -inen (e.g. definiitti ~ definiittinen).

• Enni, enin