Consonant gradation: weak and strong consonants k, p and t

Adding endings is normally quite straight forward: the stem and the ”basic form” (nominative) are the same, so you just add the ending after the word. Sometimes there are some changes in the stem, and one very common change happens with the consonants k, p and t (in phonology they are called plosives).

Sometimes these consonants are ”strong” and sometimes adding an ending ”weakens” the sound. It means that double consonant (strong) becomes one consonant (weak) or a single consonant becomes its weak counterpart or disappears.

The basic rule: strong grade is used in the syllable, which is open (ends with a vowel), weak grade when syllable is closed (ends with a consonant). Usually, this means that when you add an ending which closes the syllable (for example, the genitive ending, -n) you must use weak grade.

This rule applies to both verbs and nominals.

Consonant gradation with nominals

Basic gradation

consonant gradation, basic
Strong grade Weak grade
kk/pp/tt k/p/t
kukka
pappi
matto
kukan
papin
maton
k/p/t -/v/d
jalka
suku
koti
jalan
suvun
kodin

Other gradations

consonant gradation, other
Strong grade Weak grade
mp mm
lampi lammen
nt/lt/rt nn/ll/rr
santa sannan
santa rannan
nk ng
kenkä kengän
lke/rke/hke lje/rje/hje
kärki kärjen

Consonant gradation with verbs

Consonant gradation happens only with some verb types, namely type 1, type 3 and type 4. The basic idea is the same is with nominals and affects k, p and t sounds.

Consonant gradation with verb type 1

Some verbs belonging to type 1 undergo consonant gradation. Then the infinitive (basic form) is in strong grade, 1st and 2nd person in weak grade and 3rd person in weak grade.

consonant gradation, verb type 1
Infinitive (strong grade) 1st person (weak grade)
lukea luen
tietää tiedän
ampua ammun

Consonant gradation with verb type 3

Verbs ending with -la can undergo consonant gradation. Then the infinitive is in weak grade, personal forms are in strong grade.

consonant gradation, verb type 3
Infinitive (weak grade) 1st person (strong grade)
ajatella ajattelen
kuunnella kuuntelen

Consonant gradation with verb type 4

Verbs ending with -la can undergo consonant gradation. Then the infinitive is in weak grade, personal forms are in strong grade.

consonant gradation, verb type 4
Infinitive (weak grade) 1st person (strong grade)
hakata hakkaan
pelätä pelkään

You are here > > > > Finnish grammar: Consonant gradation