Predicate Nominals and Adjectives

To say what something is or is like — "the house is big," "she is a teacher," "the coffee is hot" — Finnish uses the verb olla ("to be") with a predicate noun or adjective. So far this looks exactly like English. The twist is the case of that predicate word. Finnish chooses between the nominative and the partitive depending on what kind of thing the subject is: a single bounded entity, or a mass, a generality, or a plurality. Getting this choice right is one of the clearest markers of a learner who has internalised how Finnish thinks about "whole" versus "part."

The basic frame: nominative predicative

When the subject is a single, countable, bounded thing, the predicate noun or adjective stands in the nominative — the plain dictionary form.

The subject (talo, hän, auto) is nominative, on links the two, and the predicate (iso, opettaja, uusi) is nominative too. This is the shape to reach for whenever you are describing one whole, discrete thing.

Mass subjects take the partitive predicative

Now change the subject to something uncountable — a substance, a liquid, an abstract mass. You cannot point at "one" of it; it has no natural boundary. Finnish marks that unboundedness by putting the predicate adjective into the partitive.

Kylmää, kuumaa, hapanta are partitive forms of kylmä, kuuma, hapan. The logic is the same logic that runs through the whole partitive case: the partitive is the case of the unbounded, the partial, the not-a-discrete-whole. Water is not a countable object, so the adjective describing it goes partitive. Say Vesi on kylmä (nominative) and you have quietly recategorised water as a single bounded item, which is not how the language treats a substance.

Plural subjects take the partitive plural

Plurality is the third trigger. When the subject is a plural, the predicate adjective or noun goes into the partitive plural — because a plurality, like a mass, is an open, uncounted set rather than one bounded whole. Note that the verb also turns plural here (ovat), agreeing in number as described on Subject–Verb Agreement.

Line these up against their singulars and the pattern is clear: Talo on iso → Talot ovat isoja; Lapsi on iloinen → Lapset ovat iloisia; Hän on opettaja → He ovat opettajia. The singular predicate is nominative singular; the plural predicate is partitive plural. A predicate never appears in the nominative plural in this construction — Talot ovat isot is wrong.

A quick reference

A helpful way to see the unity: nominative means "this bounded thing, as a whole, has this property," while partitive means "this unbounded stuff — mass or many — is characterised this way." Both a substance and a plural set are unbounded, so both pull the partitive. Fuller treatment is on the predicative partitive page.

Don't confuse the predicative with the attributive

Everything above concerns the predicative adjective — the one standing after olla. An adjective placed before its noun (an attributive) plays by completely different rules: it agrees with the noun in case and number, copying whatever case the noun is in. The nominative-vs-partitive split you just learned applies only to the predicative slot.

Look at isossa talossa: the attributive iso has taken the inessive ending to match talossa, something a predicative never does. So the same word behaves in two different ways depending on where it stands — beside the noun (agree in case) or after olla (choose nominative or partitive by boundedness). The attributive vs predicative page draws this out fully; the key is not to let the two slots blur together.

A note on honesty: the debated grey zone

Not every case is clean, and it would be misleading to pretend otherwise. A word like ilma ("air, weather") wavers: you will hear both Ilma on kaunis (treating today's weather as one bounded whole) and Ilma on kaunista (treating it as a mass), and native speakers genuinely differ. Some abstract nouns behave the same way. For the ordinary A2–B1 sentences you will actually build, the three-way table above is reliable; treat these wavering cases as things to notice in reading rather than rules to master now.

Common Mistakes

1. Nominative predicative for a mass subject. The single most common error — describing a substance as if it were a countable object.

2. Nominative plural predicative. Plural subjects need the partitive plural, not a plural nominative.

3. Forgetting the verb also goes plural. With a plural subject, on becomes ovat.

4. Partitive on a singular count subject. A single bounded thing keeps the nominative.

The takeaway is a single question you should ask before finishing any olla sentence: is my subject one bounded thing, or is it a mass or a plural? Bounded and singular → nominative predicative. Mass or plural → partitive. English marks none of this, so the choice will feel invisible at first; train yourself to see it, and your descriptions will start sounding native.