Noun Stems That Change

Level 3

In Finnish, you cannot always add endings directly to the dictionary form. Words like nainen, suomi, and uusi change their stems to naise-, suome-, and uute- before you add a case ending.

How It Works

Finnish nominals (nouns and adjectives) are grouped into types based on how they inflect. These changes create the 'vocalic stem' used for most cases like the genitive (-n) and local cases. Note that the partitive (-a/-ta/-ä/-tä) often uses a different 'consonant stem'.

  • Old -i words (-i → -e-): Many native Finnish words ending in -i change to -e-. Example: suomi (Finnish; the country is capitalized Suomi) becomes suome-. Modern loanwords like taksi do not do this.
  • -nen words (-nen → -se-): The -nen ending is replaced by -se-. Example: nainen (woman) becomes naise-.
  • -si words (-si → -te-): Words ending in -si often change to -te-. Example: uusi (new) becomes uute-. Because of consonant gradation, this 't' often weakens to 'd' (e.g., uuden).
  • -e words (-e → -ee-): Many native e-words lengthen e in their vowel stem; words such as nukke : nuken belong to a different type. Gradating members of the lengthening type undergo reverse consonant gradation (the dictionary form is weak, the stem is strong). Example: osoite (address) becomes osoittee-.
  • -us/-ys and -uus/-yys words: Words ending in -uus/-yys (like totuus) change to -uude-/-yyde- (totuude-). Words ending in -us/-ys have two main types: those derived from verbs change to -kse- (vastata → vastaus → vastaukse-), while those derived from adjectives change to -ude-/-yde- (rakas → rakkaus → rakkaude-).
  • -os/-ös words: Words ending in -os/-ös behave similarly to verb-derived -us words and change to -okse-/-ökse-. Example: päätös (decision) becomes päätökse-, and ostos (purchase) becomes ostokse-.
  • -as/-äs words: The final -s is dropped and the preceding vowel is doubled. Gradating members also undergo reverse consonant gradation; vieras has no changing consonant. Examples: vieras (guest) becomes vieraa-, rikas (rich) becomes rikkaa-, and älykäs (smart) becomes älykkää-.
  • -in words: Words ending in -in change to -ime-. Some also undergo reverse consonant gradation when a gradating consonant is present. Example: puhelin (phone) becomes puhelime-, and keitin (kettle) becomes keittime-.
  • -ton/-tön words: Words ending in -ton/-tön change to -ttoma-/-ttömä-. Example: työtön (unemployed) becomes työttömä-.
  • -ut/-yt words: Most words ending in -nut/-nyt are past active participles that change to -nee- (e.g., väsynyt becomes väsynee-). A small closed group of -ut/-yt words changes to -ue-/-ye- (e.g., olut becomes olue-).
  • -is words: Modern and spoken-language nouns ending in -is change to -ikse- (e.g., roskis becomes roskikse-). A small group of older adjectives changes to -ii- (e.g., kaunis becomes kaunii-).

Compare genitive and partitive singular:

  • suomi : suomen : suomea; taksi : taksin : taksia.
  • nainen : naisen : naista; uusi : uuden : uutta.
  • osoite : osoitteen : osoitetta.
  • totuus : totuuden : totuutta; vastaus : vastauksen : vastausta; rakkaus : rakkauden : rakkautta.
  • päätös : päätöksen : päätöstä; vieras : vieraan : vierasta; rikas : rikkaan : rikasta.
  • puhelin : puhelimen : puhelinta has no consonant gradation; keitin : keittimen : keitintä does.
  • työtön : työttömän : työtöntä; väsynyt : väsyneen : väsynyttä; olut : oluen : olutta.
  • roskis : roskiksen : roskista; kaunis : kauniin : kaunista.
  • Other consonant-ending patterns include askel : askelen : askelta; sisar : sisaren : sisarta; jäsen : jäsenen : jäsentä. The parallel word askele inflects askeleen, askelta.

These are representative word types, not an exhaustive classifier based on spelling alone. Learn a new word with its inflected forms.

Examples (5)

  1. suomi → suomen

    Finnish (language) → of Finnish

    Word by Word: Finnish → Finnish-of

    An 'old' -i word changing to an -e- stem in the genitive case.

  2. nainen → naisella

    woman → the woman has

    Word by Word: woman → woman-on

    The -nen ending changes to -se- before the adessive ending -lla is added.

  3. uusi → uuden

    new → of the new (one)

    Word by Word: new → new-of

    The -si changes to -te-, which then undergoes gradation (t → d) in the genitive.

  4. kysymys → kysymyksessä

    question → in the question

    Word by Word: question → question-in

    The -s changes to -kse- before adding the inessive ending -ssä.

  5. Opiskelen suomen kieltä.

    I am studying the Finnish language.

    Word by Word: I-study Finnish-of language-partitive

    Uses the genitive form of 'suomi' (suomen) and the partitive form of 'kieli' (kieltä).

Common Mistakes

  • Applying the -i to -e change to modern loanwords.

    Menin hotellin takseen.
    Menin hotellin taksiin.

    Modern loanwords (like 'taksi') are 'new' -i words and do not change their stem to -e-.

  • Forgetting consonant gradation in -si words.

    Ostin uuten auton.
    Ostin uuden auton.

    The -te- stem usually weakens to -de- in the genitive case.

  • Using the nominative form instead of the inflected stem.

    Puhun suomi kieltä.
    Puhun suomen kieltä.

    In the expression suomen kieli, the language name is the genitive form suomen (stem suome- plus -n). This is not a rule that every noun modifier is a genitive.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

Noun Stems That ChangeLevel 3

Learn This First

To understand nominal stem types, you must first be familiar with the Finnish case system and how endings are attached to words. Specifically, you need to understand consonant gradation, as many stem changes (like -si to -te-) follow these phonetic rules, and the genitive case, which is the most common form where these stem changes are visible.

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Patterns that build on this one.

And 1 more in the full list.