So far the partitive has marked objects and amounts. Here it does something that surprises every learner: it lands on the predicate. In a sentence like Kahvi on hyvää ("Coffee is good"), the adjective hyvää is in the partitive, not the nominative — because the subject, kahvi, is a substance rather than a single bounded thing. This is the partitive predicative, and once you see the logic behind it you will hear the difference immediately: kahvi on hyvä and kahvi on hyvää mean genuinely different things.
The rule in one line
After olla ("to be"), the predicate adjective or noun takes the partitive when the subject is unbounded — a mass, a substance, an abstract quality, or a divisible plural — and stays nominative when the subject is a single, countable, bounded thing.
Kahvi on hyvää tässä kahvilassa.
The coffee is good in this coffee shop. (mass → partitive)
Talo on iso ja valoisa.
The house is big and bright. (countable singular → nominative)
The split follows the same instinct as the rest of the case system. A house is a bounded whole, so its predicate is a bounded nominative; coffee-as-a-substance has no edges, so its predicate is an open-ended partitive. You are describing a kind or substance, not one delimited item.
Mass and substance subjects → partitive
Anything you measure rather than count — liquids, materials, food substances, weather, air — takes a partitive predicate:
Vesi on kylmää, älä mene vielä uimaan.
The water is cold, don't go swimming yet.
Maito on hapanta, kaada se pois.
The milk is sour, pour it out.
Ilma on tänään raikasta ja kirpeää.
The air is fresh and crisp today.
Tämä leipä on todella hyvää.
This bread is really good.
A predicate noun with a mass subject behaves the same way — it too goes partitive:
Kulta on metallia, ei kiveä.
Gold is a metal, not a stone.
Abstract subjects → partitive
Abstractions are unbounded in the same way substances are, so they too take a partitive predicate:
Rakkaus on sokeaa, niin sanotaan.
Love is blind, so they say.
Työ oli raskasta mutta palkitsevaa.
The work was hard but rewarding.
Divisible plural subjects → partitive plural
A plural subject is treated as an open, divisible set, so its predicate goes into the partitive plural — whether the noun is countable or not. This is where beginners most often reach wrongly for the nominative plural:
Lapset ovat iloisia, kun on lomapäivä.
The children are happy when it's a day off.
Nämä omenat ovat todella makeita.
These apples are really sweet.
Uudet naapurit ovat mukavia ja hiljaisia.
The new neighbours are nice and quiet.
Nämä kengät ovat liian kalliita.
These shoes are too expensive.
Note that iloiset, makeat, mukavat (nominative plural) would be wrong here. The predicate of a plural subject is partitive plural: iloisia, makeita, mukavia.
Countable singular subjects → nominative
When the subject is one bounded, countable thing, the predicate stays nominative — this is the ordinary case English speakers expect:
Auto on uusi ja aika kallis.
The car is new and quite expensive.
Hän on opettaja ja asuu Turussa.
She is a teacher and lives in Turku.
Tämä kirja on oikeasti mielenkiintoinen.
This book is genuinely interesting.
A predicate noun with a countable subject is likewise nominative: Hän on opettaja, Tämä on kirja — never opettajaa, kirjaa.
The meaning difference is real
This is not a decorative rule — the case changes what you are saying. Compare:
| Sentence | Reading |
|---|---|
| Kahvi on hyvää. | Coffee (the drink, as a substance) is good. |
| Kahvi on hyvä. | The coffee (this particular one) is a good one. |
| Suklaa on hyvää. | Chocolate is good (as a food). |
| Tämä suklaa on hyvä. | This (bar of) chocolate is a good one. |
Using the nominative hyvä with a mass subject does not just sound off — it forces a bounded, "one particular portion" reading. If you mean coffee as a drink, you must say hyvää. English collapses both into "is good," which is exactly why this is hard: the distinction simply is not marked in your source language. This partitive predicative signals "as a kind or substance," and there is no shortcut but to internalise which subjects are bounded and which are not.
Harmony on the predicate
The predicate ending harmonizes like any other partitive: hyvää (back-vowel stem) but kylmää (front-vowel stem), kuumaa but kirpeää. Attributive agreement — the adjective standing before its noun, as in hyvä kahvi — is a separate matter, covered on attributive vs predicative.
Common Mistakes
❌ Kahvi on hyvä.
Wrong for coffee-as-a-drink — a mass subject takes a partitive predicate: hyvää. (Nominative hyvä means one specific cup is a good one.)
✅ Kahvi on hyvää.
Coffee is good.
❌ Vesi on kylmä.
Incorrect — vesi is a mass, so the predicate is partitive: kylmää.
✅ Vesi on kylmää.
The water is cold.
❌ Lapset ovat iloiset.
Incorrect — a plural subject takes a partitive-plural predicate: iloisia, not the nominative plural iloiset.
✅ Lapset ovat iloisia.
The children are happy.
❌ Talo on isoa.
Incorrect — a countable singular subject keeps the nominative: talo on iso.
✅ Talo on iso.
The house is big.
❌ Nämä omenat ovat makeat.
Incorrect — plural subject → partitive plural predicate: makeita.
✅ Nämä omenat ovat makeita.
These apples are sweet.
Key Takeaways
- After olla, an unbounded subject (mass, substance, abstract) takes a partitive predicate: kahvi on hyvää, vesi on kylmää, rakkaus on sokeaa.
- A divisible plural subject takes a partitive-plural predicate: lapset ovat iloisia, omenat ovat makeita.
- A bounded countable singular subject keeps the nominative: talo on iso, hän on opettaja.
- The case carries meaning: hyvää = "as a substance/kind," hyvä = "this one particular item is good."
- Keep the nominative plural only for identity, not description (nämä ovat minun avaimeni).
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Start learning Finnish→Related Topics
- Partitive with Mass and Uncountable NounsA2 — Mass nouns take the partitive for an indefinite amount — ostan maitoa, juon vettä — while the total form (ostan leivän) means a whole, bounded unit.
- Partitive Predicatives: Kahvi on kuumaaB1 — After olla, a mass or plural subject takes a partitive predicative adjective (kahvi on kuumaa, lapset ovat pieniä); a bounded singular stays nominative.
- The Partitive: Finland's Most Important CaseA1 — The partitive marks unbounded quantity and unfinished events — after numbers, under negation, with mass nouns, and as a partial object; the hub for the whole partitive.
- Attributive vs Predicative PositionA2 — An attributive adjective copies its noun's case (vanhassa talossa); a predicative adjective after olla resets to the nominative (talo on vanha).
- Predicate Nominals and AdjectivesA2 — Finnish links subject and predicate with olla, taking a nominative predicative for bounded wholes but the partitive for mass nouns and plurals.