Choosing the Object Case

Level 4

Finnish uses three main cases for direct objects: the partitive, the genitive, and the nominative. The choice depends on the 'completeness' of the action and the sentence type.

How It Works

In Finnish, the object case tells you more than just what is being acted upon; it tells you if the action is finished or if the amount is limited (the partitive indicates an unlimited, indefinite, or mass amount, while the total object indicates a limited, bounded, or whole amount).

Important Rule Hierarchy: Negation and partitive verbs trump all other rules. If the action affecting the object is negated or the verb requires a partitive object in that meaning, use the partitive regardless of amount.

1. The Partitive Object (Singular: -a/-ä, -ta/-tä, -tta/-ttä; Plural: -ja/-jä, -ita/-itä, -ta/-tä)
Use the partitive when:

  • The action is ongoing or unfinished (e.g., 'I am reading the book').
  • The sentence is negative (e.g., 'En lue kirjaa' - I am not reading the book).
  • The object is an indefinite amount, including an unspecified amount of a mass noun (e.g., 'I drink coffee').
  • The verb is a partitive verb (e.g., rakastaa, auttaa, odottaa), which always requires a partitive object.

2. The Total Object (Genitive, Nominative, or Plural -t)
Use a total object when the action has a definitive end point or result (completed or will be completed), and it concerns a whole, specific thing.

  • Genitive (-n): Used for singular objects in standard active sentences (e.g., 'Ostan auton' - I will buy the car).
  • Nominative: Used for singular objects in 1st and 2nd person imperatives, passive sentences, and necessive (must) sentences (triggered by verbs and structures like täytyy, pitää, kannattaa, and on pakko).
  • Plural Total Object: When a plural noun is a total object, it always uses the nominative plural (-t) form (e.g., 'Ostan kirjat' - I will buy the books).

3. Personal Pronouns and 'kuka'
Personal pronouns and the interrogative pronoun 'kuka' (who) have a special accusative form ending in -t (minut, sinut, hänet, kenet, etc.) when they are total objects. Unlike regular nouns, these pronouns keep this -t ending even in passive, imperative, or necessive sentences where a noun would become nominative.

4. Numbers as Objects
With ordinary cardinal numbers two and higher, the counted noun is partitive singular in these nominative/partitive object phrases. This does not cover ordinal numbers, plural numerals or other case constructions. For ordinary cardinal numbers two and higher, a total object uses the bare number, not its genitive: kaksi autoa, not kahden autoa. A partitive object inflects the number as partitive (e.g., 'Ostan kaksi autoa' - total object, 'En osta kahta autoa' - partitive object).

Infinitives Do Not Automatically Mean Nominative
Compare Haluan ostaa auton (I want to buy a car), where the active subject construction gives the total object auton, with Minun täytyy ostaa auto (I must buy a car), where the necessive construction gives auto. Learn the governing construction as well as the infinitive. A bounded amount of a substance can also be a total object: Join kahvin (I drank the coffee).

Examples (5)

  1. Luen kirjaa.

    I am reading a/the book.

    Word by Word: I-read book-(partitive).

    The partitive is used here because the action is ongoing (process).

  2. Luen kirjan.

    I will read the (whole) book.

    Word by Word: I-read book-(genitive).

    The genitive total object indicates the action will be completed (result).

  3. En osta autoa.

    I am not buying / will not buy the car.

    Word by Word: Not I-buy car-(partitive).

    Here the buying is negated, so autoa is partitive.

  4. Osta auto!

    Buy the car!

    Word by Word: Buy car-(nominative)!

    In imperative (command) sentences, the total object is in the nominative form.

  5. Minun täytyy ostaa auto.

    I must buy a car.

    Word by Word: My must to-buy car-(nominative).

    After 'täytyy', the total object takes the nominative form instead of the genitive.

Common Mistakes

  • Using the genitive plural for a plural total object.

    Ostan kirjojen.
    Ostan kirjat.

    A plural total object uses nominative plural kirjat, not genitive plural kirjojen.

  • Forgetting the partitive in negative sentences.

    En osta auto.
    En osta autoa.

    When the action affecting the object is negated, use the partitive: en osta autoa. A negative verb elsewhere in a larger sentence does not automatically control every embedded object.

  • Using a total object when you intend to describe only the process.

    Different MeaningSyön omenan nyt.
    Syön omenaa nyt.

    Syön omenaa nyt describes the process. Syön omenan nyt is also grammatical, but presents eating the whole apple as a bounded action or intention. Being in the present tense does not itself require the partitive.

How It Connects

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

Choosing the Object CaseLevel 4

Learn This First

The 'object rules summary' is a high-level synthesis of Finnish object marking. To understand it, a learner must already be familiar with the three primary ways an object is marked: the partitive (for incomplete or negative actions), the genitive (for completed singular actions), and the nominative (for specific structures like imperatives, passives, and necessives).

Learn Next

Patterns that build on this one.