Consonant gradation in partitive plural

Strong vs. Weak Grades in Plurals

Adding the nominative plural -t usually triggers the weak grade of consonants (like K, P, and T) because it closes the final syllable.

However, partitive plural endings (like -ja, -jä, -a, ) typically leave the syllable open, keeping the word in the strong grade — matching its dictionary form.

Base Word (Strong)Nominative Plural (Weak)Partitive Plural (Strong)
pelto (lt)pellot (ll)peltoja (lt)
sika (k)siat (dropped)sikoja (k)
aita (t)aidat (d)aitoja (t)

Notice how the partitive plural keeps the strong lt in peltoja:

The fields are green here.
Pellot ovat täällä vihreitä.
The farmers buy new fields.
Isännät ostavat uusia peltoja.

Disappearing K and RK

A single k often disappears in the weak nominative plural but remains in the strong partitive plural. Similarly, rk weakens to r but stays rk in the partitive plural.

The pigs sleep on the farm.
Siat nukkuvat maatilalla.
We have a lot of pigs today.
Meillä on tänään paljon sikoja.
Those oxen stand in the meadow.
Nuo härät seisovat niityllä.
Do you see those oxen?
Näetkö noita härkiä?

Double consonants like kk weaken to a single k in the nominative plural but stay double in the partitive plural.

The roosters sit on the old fence.
Kukot istuvat vanhalla aidalla.
I do not want to listen to roosters.
En halua kuunnella kukkoja.

The T and TT Shifts

A single t softens to d in the weak grade, while tt weakens to a single t. The partitive plural remains strong.

The new fences are behind the cowshed.
Uudet aidat ovat navetan takana.
We are buying new fences tomorrow.
Ostamme huomenna uusia aitoja.
Cowsheds are often red.
Navetat ovat usein punaisia.
Why are you building these cowsheds?
Miksi rakennatte näitä navettoja?