Inflecting Numbers

Level 3

In Finnish, when a noun takes a case ending (like 'in', 'from', or 'to'), the number modifying it must take the exact same ending. This is called numeral congruence.

How It Works

0. The Baseline Rule
Before looking at other cases, it is important to understand the basic rule: when a number (from 2 upwards) is in the nominative or accusative case, the noun that follows it must be in the partitive singular. For example, kaksi autoa (two cars), not kaksi auto. This contrasts with the agreement rule used in other cases.

1. The Agreement Rule
When you use a number with a noun in a case like the inessive (-ssa) or allative (-lle), you must inflect both words. Crucially, the noun remains in the singular form, even though the meaning is plural.

2. The Inflectional Stems
Numbers have special stems. The weak stems (e.g., yhde-, kahde-, viide-) are used for the genitive and most local cases like -ssa, -lla, and -lle. The strong stems (e.g., yhte-, kahte-, viite-, kuute-) are required for the illative and essive cases. The partitive case for numbers 1, 2, 5, and 6 is formed from their consonant stems (yht-, kaht-, viit-, kuut-).

  • 1 (yksi): weak stem yhde- (yhden, yhdessä), strong stem yhte- (yhteen, yhtenä), consonant stem yht- (yhtä)
  • 2 (kaksi): weak stem kahde- (kahden, kahdessa), strong stem kahte- (kahteen, kahtena), consonant stem kaht- (kahta)
  • 3 (kolme): stem kolme- (kolmessa)
  • 4 (neljä): stem neljä- (neljässä)
  • 5 (viisi): weak stem viide- (viiden, viidessä), strong stem viite- (viiteen, viitenä), consonant stem viit- (viittä)
  • 6 (kuusi): weak stem kuude- (kuuden, kuudessa), strong stem kuute- (kuuteen, kuutena), consonant stem kuut- (kuutta)
  • 7-10: For most cases, drop the final consonant (e.g., kymmenen -> kymmene- + ssä). The partitive forms for 7-9 lengthen the final vowel: seitsemää, kahdeksaa, yhdeksää. The partitive of 10 retains the consonant: kymmentä. Note that these numbers do not have consonant gradation (no weak/strong pairs). Crucially, because their stems end in a vowel and the genitive suffix is -n, their genitive forms look exactly identical to their nominative forms (seitsemän, kahdeksan, yhdeksän, kymmenen).

3. Plural-Only Nouns (Plurale Tantum)
If a noun is only used in the plural (like häät 'wedding' or sakset 'scissors'), the number must also be in the plural form of that case. For example: kaksissa häissä (in two weddings) instead of the singular kahdessa.

4. Compound Numbers
In formal Finnish, every part of a large number inflects. For example, 'in 22' is kahdessakymmenessäkahdessa. The only exception is the suffix -toista (used for teens), which never changes: 'in 12' is kahdessatoista. In spoken Finnish, however, often only the last digit inflects (e.g., kakskytkahdessa).

5. The Number One (yksi) and Zero (nolla)
While all numbers agree with the noun in the genitive and locative cases, yksi is unique because it also agrees in the nominative and accusative without triggering the partitive for the noun. Furthermore, when used as a total object, 'yksi' takes the genitive-accusative '-n' (e.g., Näen yhden auton), whereas numbers 2 and up remain in the nominative form (e.g., Näen kaksi autoa). The number zero (nolla) behaves like numbers 2 and up, triggering the partitive singular in the basic form (e.g., nolla astetta).

Examples (5)

  1. Asun kahdessa talossa.

    I live in two houses.

    Word by Word: I-live two-in house-in.

    Both 'kaksi' (stem kahde-) and 'talo' take the inessive ending -ssa. The noun remains singular.

  2. Annoin kirjan viidelle oppilaalle.

    I gave the book to five students.

    Word by Word: I-gave book five-to student-to.

    The number 'viisi' (stem viide-) and the noun 'oppilas' both take the allative ending -lle.

  3. Tulen kotiin kahdeksalta.

    I am coming home at eight.

    Word by Word: I-come home eight-from.

    Time expressions often use the ablative case (-lta). The number 'kahdeksan' drops its 'n' to form the stem 'kahdeksa-' before the ending.

  4. Hän asuu kolmannessa kerroksessa.

    He/she lives on the third floor.

    Word by Word: He/she lives third-in floor-in.

    Ordinal numbers (first, second, third) also follow the agreement rule.

  5. Ostin lahjan yhdelle ystävälle.

    I bought a gift for one friend.

    Word by Word: I-bought gift one-to friend-to.

    The number 'yksi' (stem yhde-) agrees with the noun in the allative case.

Common Mistakes

  • Keeping the noun in the partitive when the number is inflected.

    Asun kahdessa taloa.
    Asun kahdessa talossa.

    The 'number + partitive' rule only applies in the nominative/accusative. In other cases, the noun must match the case of the number.

  • Using the plural case ending on the noun for regular objects.

    viidelle oppilaille
    viidelle oppilaalle

    Even though the meaning is plural, the noun stays in the singular form when following an inflected number, unless it is a plural-only noun like 'häät'.

  • Inflecting the '-toista' part of teen numbers.

    kahdessatoistassa
    kahdessatoista

    The suffix '-toista' is invariant; only the first part of the number inflects.

How It Connects

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

Inflecting NumbersLevel 3

Learn This First

To inflect numbers in cases, you first need to be familiar with the basic cardinal numbers (1-10). Since numbers in Finnish act like adjectives when modifying a noun, you must understand the general case system and the principle of agreement, where the modifier (the number) takes the same case ending as the noun it describes.

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Patterns that build on this one.