Adjective Agreement in Finnish

Overview

In Finnish, adjectives must agree with the noun they modify in both number and case. This means that when a noun changes to partitive, plural, or any other case, the adjective in front of it changes too. This is one of the fundamental grammar patterns you learn at the A1 level, and it applies consistently throughout the language.

For English speakers, adjective agreement is a new concept since English adjectives never change form ("big house," "big houses," "in a big house" — "big" stays the same). In Finnish, you need to match the adjective to the noun at all times, which requires knowing how both words decline.

The good news is that adjective agreement follows the same case patterns as nouns. Once you know how to form noun cases, you can apply the same rules to adjectives.

How It Works

Basic agreement: nominative

Singular	Plural	English
iso talo	isot talot	big house(s)
pieni koira	pienet koirat	small dog(s)
kaunis päivä	kauniit päivät	beautiful day(s)

Agreement in common cases

Case	Singular	Plural	English
Nominative	iso talo	isot talot	big house(s)
Genitive	ison talon	isojen talojen	of the big house(s)
Partitive	isoa taloa	isoja taloja	big house(s) (partitive)
Inessive	isossa talossa	isoissa taloissa	in the big house(s)
Adessive	isolla talolla	isoilla taloilla	on/at the big house(s)
Illative	isoon taloon	isoihin taloihin	into the big house(s)

With numbers

After numbers 2+, the noun takes partitive singular, and so does the adjective:

Finnish	English
yksi iso talo	one big house
kaksi isoa taloa	two big houses
kolme kaunista päivää	three beautiful days

Predicate adjectives

When an adjective is a predicate (after "olla"), it agrees in number but stays in nominative:

Finnish	English
Talo on iso.	The house is big.
Talot ovat isot.	The houses are big.
Koira on pieni.	The dog is small.
Koirat ovat pienet.	The dogs are small.

Examples in Context

Finnish	English	Note
Iso talo on kadulla.	A big house is on the street.	Nominative agreement
Näen ison talon.	I see the big house.	Genitive agreement (object)
Asun isossa talossa.	I live in a big house.	Inessive agreement
Punainen auto on nopea.	The red car is fast.	Two adjectives
Ostan uuden kirjan.	I buy a new book.	Genitive agreement
Vanhalla kadulla on puita.	On the old street there are trees.	Adessive agreement
Kolme pientä kissaa	Three small cats	Number + partitive agreement
Kauniit kukat ovat pöydällä.	The beautiful flowers are on the table.	Plural nominative
Tämä on hyvä ravintola.	This is a good restaurant.	Attributive adjective
Ruoka on hyvää.	The food is good.	Predicate + partitive (mass noun)
Uudessa talossa on iso piha.	In the new house there is a big yard.	Inessive agreement
He ovat mukavia ihmisiä.	They are nice people.	Partitive plural (predicate)

Common Mistakes

Not changing the adjective case

• Wrong: Asun iso talossa.
• Right: Asun isossa talossa.
• Why: The adjective must be in the same case as the noun. If the noun is inessive (talossa), the adjective must be too (isossa).

Forgetting plural agreement

• Wrong: Iso talot ovat kadulla.
• Right: Isot talot ovat kadulla.
• Why: When the noun is plural, the adjective must also be in the plural form.

Wrong agreement after numbers

• Wrong: kaksi isot talot (plural instead of partitive singular)
• Right: kaksi isoa taloa
• Why: After numbers 2+, both adjective and noun take the partitive singular, not the plural.

Mixing predicate and attributive forms

• Wrong: Talo on isossa. (case form as predicate)
• Right: Talo on iso.
• Why: Predicate adjectives (after olla) stay in nominative case. Only attributive adjectives (before the noun) take the noun's case.

Practice Tips

1. Case chain practice: Take one adjective-noun pair (e.g., iso talo) and decline it through all major cases: iso talo, ison talon, isoa taloa, isossa talossa, isolle talolle... This builds automatic agreement patterns.
2. Description game: Describe objects around you with adjectives in different cases: Istun punaisella tuolilla. Katselen kaunista maisemaa. Kävelen pitkällä kadulla.
3. Number + adjective drill: Count objects with adjectives: yksi punainen auto, kaksi punaista autoa, kolme punaista autoa. Pay attention to how both adjective and noun shift to partitive after "one."

Related Concepts

• Prerequisite: Nominative and Partitive Cases — the basic case system adjectives follow
• Next steps: Comparison of Adjectives — comparative and superlative forms
• Next steps: Adverbs of Manner — how adjectives become adverbs
• Next steps: Expressing Opinions and Feelings — using adjectives to express emotions