-toista

Teens with -toista

Level 1

Numbers 11–19 are formed by adding -toista to the basic numbers 1–9 (e.g., yksi + toista = yksitoista).

How It Works

In Finnish, the 'teen' numbers (11–19) follow a unique historical logic. While English uses '-teen' (related to 'ten'), Finnish uses -toista, which is the partitive form of toinen (second). Note that 10 is simply kymmenen and does not use this suffix.

  • Formation: Take the numbers 1-9 and simply add -toista to the end.
  • Spelling: These are always written as one single word without spaces or hyphens.
  • Inflection: When you need to use a case (like the genitive or adessive), only the first part of the number inflects. The suffix -toista is 'frozen' and never changes. This same rule applies to ordinal numbers (e.g., kahdestoista, the 12th).
  • Spoken Finnish: In spoken Finnish, the final '-a' is often dropped (e.g., yksitoist), and the unit is shortened (e.g., kakstoist).

Examples (5)

  1. yksitoista, kaksitoista, kolmetoista

    eleven, twelve, thirteen

    Word by Word: one-of-the-second, two-of-the-second, three-of-the-second

    Basic nominative forms of the 'teen' numbers.

  2. Hän on viisitoista vuotta vanha.

    He/she is fifteen years old.

    Word by Word: He/she is five-of-the-second years old.

    Standard usage of a 'teen' number in a sentence.

  3. Syön brunssia yhdeltätoista.

    I eat brunch at eleven.

    Word by Word: I-eat brunch eleven-at.

    Here 'yksi' takes the ablative ending to mean 'at eleven', becoming 'yhdeltä', while '-toista' stays unchanged. The plain clock reading uses the nominative: Kello on yksitoista.

  4. Asun talossa numero neljätoista.

    I live in house number fourteen.

    Word by Word: I-live house-in number four-of-the-second.

    Numbers used as names or labels stay in the nominative form.

  5. Mä oon kakstoist.

    I'm twelve.

    Word by Word: I am two-teen.

    A common spoken Finnish (puhekieli) version of 'kaksitoista'.

Common Mistakes

  • Applying the -toista pattern to the number 10.

    kymmenentoista
    kymmenen

    The number 10 is simply 'kymmenen'. The -toista pattern only begins at 11 (yksitoista).

  • Inflecting both parts of the word.

    kahdellatoistalla
    kahdellatoista

    Unlike the 'tens' (20, 30, etc.), where both parts inflect, in the 'teens' (11-19), only the first part changes. The suffix -toista never takes an ending.

  • Using kaksikymmentä for 12.

    Different Meaningkaksikymmentä
    kaksitoista

    Kaksikymmentä means 20 (two tens), while kaksitoista means 12 (two of the second ten).

How It Connects

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

-toistaLevel 1Teens with -toista

Learn This First

To form the 'teen' numbers in Finnish, you simply need to know the basic numerals from one to nine and append the suffix '-toista' to them.

Words in This Pattern

-toista