Past tense vowel changes for verb type 1 (-o- / -i-)

To form the past tense (imperfect), add the marker -i- to the verb's stem. For Type 1 verbs ending in -a or , the final vowel mutates or drops to accommodate the -i-.

Dropping -a and

The final vowel drops entirely if:

  • The verb ends in (e.g., näyttäänäytti)
  • The verb ends in -a and the first vowel is o or u (e.g., ostaaosti)
  • The verb has three or more syllables (e.g., kirjoittaakirjoitti)
I bought a beautiful souvenir from Estonia.
Ostin kauniin matkamuiston Virosta.
My girlfriend wrote three postcards.
Tyttöystäväni kirjoitti kolme postikorttia.

Consonant gradation still applies in the past tense! For example, the strong tt in ottaa weakens to t in otimme because the -mme ending closes the syllable.

We took a photograph in the museum.
Otimme valokuvan museossa.

Changing -a to -o-

If a two-syllable verb ends in -a and its first vowel is a, e, or i (like antaa, kantaa, or maksaa), the final -a changes to -o- before the -i-.

This local handicraft cost twenty euros.
Tämä paikallinen käsityö maksoi kaksikymmentä euroa.
Father gave me a beautiful piece of jewelry.
Isä antoi minulle kauniin korun.

Consonant gradation applies here as well, such as the strong ht in vaihtaa weakening to hd in vaihdoimme.

My boyfriend exchanged money and carried my bag.
Poikaystäväni vaihtoi rahaa ja kantoi laukkuni.
We exchanged a hundred euros in the bank.
Vaihdoimme sata euroa pankissa.

These verbs are incredibly common when describing travel experiences, meaning you will often see both patterns used side-by-side.

The tourist took a photograph and the guide gave a map.
Turisti otti valokuvan ja opas antoi kartan.