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Consonant Gradation Overview – Astevaihtelu – KPT-vaihtelu

Consonant gradation (astevaihtelu or KPT-vaihtelu) is an important topic in Finnish. This page combines the information of my other pages related to astevaihtelu in one big article. This means it can be overwhelming. If you want to focus on one type of consonant gradation at a time, you can look at the other related pages on my website:

Below, you can find a more detailed list of the strong and weak forms.

1. What is Consonant Gradation?

Consonant gradation is called astevaihtelu or KPT-vaihtelu in Finnish. It’s a phenomenon you are going to run into all the time when learning Finnish.

Consonant gradation only affects certain consonants (K, P and T). That’s why it is often called “KPT-vaihtelu” in Finnish courses. The consonants K, P and T can change when they appear in the middle of a word. This change takes place when we add a case ending to a word. Consonants can have a “strong” grade and a “weak” grade. I have the tendency to color-code these grades: strong is red, green is weak.

Different words and different verbs undergo a different system of consonant gradation. There are two separate groups for nouns and adjectives. For verbs, each Finnish verbtype has its own pattern.

2. Which Consonants Change?

Consonant gradation only happens to the following consonants.

From strong to weak

Strong Weak Noun Example Verb Example
kk k pankki → pankissa nukkua → minä nukun
pp p kauppa → kaupassa tappaa → minä tapan
tt t konsertti → konsertissa ottaa → minä otan
nt nn Skotlanti → Skotlannissa antaa → minä annan
nk ng kaupunki → kaupungissa tinkiä → minä tingin
mp mm kampa → kammassa ampua → minä ammun
lt ll silta → sillalla viheltää → minä vihellän
rt rr virta → virralla kertoa → minä kerron
t d pöytä → pöydällä pyytää → minä pyydän
k Ø polku → polulla jakaa → minä jaan
k v luku → luvussa
p v apu → avulla leipoa → minä leivon
lk(i) lj(e) lki → jäljessä sulkea→ suljen
rk(i) rj(e) rki → järjellä rkeä → särjen

From weak to strong

Weak Strong Noun Example Verb Example
k kk liike → liikkeessä pakata → pakkaan
p pp opas → oppaassa hypätä → hyppään
t tt osoite → osoitteessa mitata → mittaan
nn nt ranne → ranteessa suunnata → suuntaan
ng nk kangas → kankaassa hangata → hankaan
mm mp hammas → hampaassa kammata → kampaan
ll lt allas → altaalla vallata → valtaan
rr rt murre → murteessa kerrata → kertaan
d t hidas → hitaassa pudota → putoan
Ø k koe → kokeessa maata → makaan
v p varvas → varpaassa tavata → tapaan
hje hke lahje → lahkeessa valjeta → valkenen
lje lke hylje → hylkeessä rohjeta → rohkenen
rje
rke
tarjeta → tarkenen

3. KPT-vaihtelu in Nouns

Nouns, adjectives and numbers can belong to one of two groups: wordtype A and wordtype B.

3.1. Wordtype A Consonant Gradation

In the beginning of your studies, you will generally only find one type of consonant gradation in courses and course books. This is wordtype A consonant gradation. Your teacher won’t be mentioning this term in the beginning. The term is only useful once you’re ready to study wordtype B.

If you’ve been studying Finnish for a short period of time, focus on this first type of consonant gradation until you have a decent grasp on it before learning wordtype B. Save yourself some confusion!

3.1.1. Which words belong to wordtype A?

Wordtype A consists of the following wordtypes:

  • Words ending in a single vowel: o, ö, u, y, a, ä, i (except for -e!)
  • Words ending in two vowels: e.g. museo, vihreä, televisio
  • Some words ending in -us: e.g. salaisuus, rakkaus

3.1.2. Which forms are strong and weak in wordtype A?

Strong forms for wordtype A:

Weak forms for wordtype A:

  • T-plural (-t): pankit, pöydät, matot
  • Genitive (-n): pankin, pöydän, maton
  • Inessive (-ssa): pankissa, pöydässä, matossa
  • Elative (-sta): pankista, pöydästä, matosta
  • Adessive (-lla): pankilla, pöydällä, matolla
  • Ablative (-lta): pankilta, pöydältä, matolta
  • Allative (-lle): pankille, pöydälle, matolle
  • Translative (-ksi): pankiksi, pöydäksi, matoksi
  • Abessive (-tta): e.g. ehdoitta (rare case)
  • Instructive (-in): e.g. täysin rinnoin (rare case)
  • Comparative (-mpi): e.g. heikompi, aidompi, tutumpi
  • Superlative (-in): e.g. heikoin, aidoin, tutuin
  • Plural location cases (-ssa, -lla, -sta, -lta, -lle): pankeissa, pöydiltä, matoille
  • Plural translative: pankeiksi, pöydiksi, matoiksi

3.2. Wordtype B Consonant Gradation

Wordtype B is less common than wordtype A. If you’ve been studying for a short period of time, you probably haven’t learned yet about wordtype B. If that’s the case, focus on wordtype A consonant gradation until you have a decent grasp on it before learning wordtype B. Save yourself some confusion!

3.2.1. Which words belong to wordtype B?

Wordtype B consists of the following wordtypes:

  • Words ending in -e: e.g. parveke, hylje, murre
  • Words ending in -in: e.g. kahvinkeitin, tuuletin, soitin
  • Words ending in -as: e.g. rakas, puhdas, hammas
  • Words ending in -ton: e.g. työtön, arvoton, unohtumaton
  • Words ending in -tar: e.g. ystävätär, kuningatar, opettajatar
  • Some words ending in -is: e.g. raitis, ruis

3.2.2. Which forms are strong and weak in wordtype B?

For wordtype B, the nominative of the word (the basic form) will always be weak. All the other forms will be strong, except for the partitive.

Strong forms for wordtype B:

  • T-plural (-t, mitkä?): osoitteet, hampaat, soittimet
  • Genitive (-n, minkä?): osoitteen, hampaan, soittimen
  • Inessive (-ssa, missä?): osoitteessa, hampaassa, soittimessa
  • Elative (-sta, mistä?): osoitteesta, hampaasta, soittimesta
  • Illative (-Vn, -seen, mihin?): osoitteeseen, hampaaseen, soittimeen
  • Adessive (-lla, millä?): osoitteella, hampaalla, soittimella
  • Ablative (-lta, miltä?): osoitteelta, hampaalta, soittimelta
  • Allative (-lle, mille?): osoitteelle, hampaalle, soittimelle
  • Translative (-ksi): osoitteeksi, hampaaksi, soittimeksi
  • Essive (-na): osoitteena, hampaana, soittimena
  • Abessive (-tta): osoitteetta, hampaatta (rare case)
  • Instructive (-in): e.g. pitkin hampain (rare case)
  • Comparative (-mpi): rikkaampi, puhtaampi, arvottomampi
  • Superlative (-ni): rikkain, puhtain, arvottomin
  • Plural partitive: osoitteita, hampaita, soittimia
  • Plural genitive: osoitteiden, hampaiden, soittimien
  • Plural illative: osoitteisiin, hampaisiin, soittimiin
  • Plural location cases (-ssa, -lla, -sta, -lta, -lle): osoitteissa, hampailla, soittimille
  • Plural essive: osoitteina, hampaina, soittimina
  • Plural translative: osoitteiksi, hampaiksi, soittimiksi

Weak forms for wordtype B:

  • Basic form (mikä?): osoite, rikas, puhdas
  • Partitive (mitä?): osoitetta, rikasta, puhdasta

4. KPT-Vaihtelu in Verbs

In order to learn how verbs undergo consonant gradation, it’s very helpful to know the Finnish verbtypes.

4.1. Verbtype 1 Consonant Gradation

For verbtype 1, the infinitive of the verb (the basic form) will always be strong. Minä, sinä, me and te will become weak when you add the personal ending, while hän and he will remain as they were in the basic form. The present and past tense for verbtype 1 will follow this same pattern.

We could rephrase this by saying that verbtype 1 consonant gradation takes place when you add the following personal endings: -n, -t, -mme, -tte. As you can see, this leaves the third person forms out.

Strong forms for verbtype 1:

  • Basic form (infinitive of the verb): nukkua, auttaa
  • Positive present tense (hän and he): nukkuu, nukkuvat, auttaa, auttavat
  • Positive imperfect tense (hän and he): nukkui, nukkuivat, auttoi, auttoivat
  • Negative imperfect tense (all persons): e.g. en nukkunut, emme auttaneet
  • The NUT-participle: nukkunut, auttanut 
  • Conditional (all persons, positive + negative): e.g. nukkuisin, en nukkuisi, auttaisimme, en auttaisi
  • Plural imperative (positive + negative): Nukkukaa! Älkää nukkuko! Auttakaa! Älkää auttako!
  • The VA-participle: nukkuva, auttava
  • The jussiivi (positive + negative): Nukkukoon! Älköön nukkuko! (advanced topic)

Weak forms for verbtype 1:

  • Positive present tense (minä, sinä, me and te): e.g. nukun, nukut, autamme, autatte
  • Negative present tense (all persons): e.g. en nuku, ei nuku, et auta, eivät auta
  • Imperfect tense (minä, sinä, me and te): e.g. nukuin, nukuit, autoimme, autoitte
  • Singular imperative (positive + negative): Nuku! Älä nuku! Auta! Älä auta!
  • Present passive (positive + negative): nukutaan, ei nukuta, autetaan, ei auteta
  • Past passive (positive + negative): nukuttiin, ei nukuttu, autettiin, ei autettu
  • The TU-participle: nukuttu, autettu
  • Passive conditional (positive + negative): nukuttaisiin, ei nukuttaisi, autettaisiin, ei autettaisi
  • Passive imperative (positive + negative): nukuttakoon, älköön nukuttako, autettakoon (advanced)
  • The TAVA-participle: nukuttava, autettava

4.2. Verbtype 2 Consonant Gradation

Verbtype 2 normally doesn’t have any consonant gradation. However, there are two verbs that do have consonant gradation: nähdä and tehdä. These two verbs follow a similar pattern to verbtype 1, exception of some forms that are based on the infinitive of the verb (so näh- and teh- without consonant gradation).

The strong form’s -k- (e.g. tekee) disappears in the weak forms (e.g. teemme)

Strong forms for tehdä and nähdä:

  • Positive present tense (hän and he): tekee, tekevät, kee, näkevät
  • Imperfect tense (hän and he): teki, tekivät, näki, näkivät
  • Conditional (all persons, positive + negative): e.g. tekisin, en tekisi, näkisit, emme näkisi
  • The VA-participle: tekevä, näkevä

Weak forms for tehdä and nähdä:

  • Positive present tense (minä, sinä, me and te): e.g. teen, teemme, näet, näette
  • Negative present tense (all persons): e.g. en tee, eivät tee, ei näe, emme näe
  • Positive imperfect tense (minä, sinä, me and te): e.g. tein, teimme, näit, näitte
  • Singular imperative (positive + negative): Tee! Näe! Älä tee! Älä näe!

Forms that don’t have KPT:

Some forms of the verbs tehdä and nähdä are based on their infinitive, which means their stem is teh- and näh- without any consonant gradation.

4.3. Verbtype 3 Consonant Gradation

For verbtype 3, some course books (and teachers) might call this “reverse consonant gradation”, but this is an inaccurate term. It’s true for some forms that verbtype 1’s strong forms will be weak in verbtype 3 (e.g. in the basic form: ottaa vs. ajatella). However, it’s not the case for every form.

Strong forms for verbtype 3:

  • Present tense (all persons, positive + negative): e.g. ajattelen, en ajattele, ompelette, ette ompele
  • Positive imperfect tense (all persons): eg. ajattelin, ajattelimme, ompelitte, ompelivat
  • Conditional (all persons, positive + negative): e.g. ajattelisit, en ajattelisi, ompelisin, eivät ompelisi
  • Singular imperative (positive + negative): Ajattele! Ompele! Älä ajattele! Älä ompele!
  • The VA-participle: ajatteleva, ompeleva

Weak forms for verbtype 3:

4.4. Verbtype 4 Consonant Gradation

The weak and strong forms of verbtype 4 match up with the ones for verbtype 3 and 6.

Strong forms for verbtype 4:

  • Positive present tense (all persons): e.g. tapaan, tapaamme, kampaat, kampaavat
  • Negative present tense (all persons): e.g. en tapaa, eivät tapaa, ei kampaa, emme kampaa
  • Positive imperfect tense (all persons): e.g. tapasin, tapasitte, kampasit, kampasimme
  • Conditional (all persons, positive + negative): e.g. tapaisin, en tapaisi, kampaisivat, eivät kampaisi
  • Singulat imperative (positive + negative): Tapaa! Älä tapaa! Kampaa! Älä kampaa!
  • The VA-participle: tapaava, kampaava

Weak forms for verbtype 4:

4.5. Verbtype 5 Consonant Gradation

Verbtype 5 doesn’t have consonant gradation at all.

4.6. Verbtype 6 Consonant Gradation

For verbtype 6, the weak and strong forms match up with the ones for verbtype 3 and 4.

Strong forms for verbtype 6:

  • Positive present tense (all persons): e.g. kalpenee, kalpenevat, lämpenee, lämpenemme
  • Negative present tense (all persons): e.g. en kalpene, emme kalpene, ei lämpene, eivät lämpene
  • Positive imperfect tense (all persons): eg. kalpeni, kalpenivat, lämpeni, lämpenimme
  • Conditional (all persons, positive + negative): e.g. kalpenisi, eivät kalpenisi, lämpenisi, ette lämpenisi
  • Singular imperative (positive + negative): Kalpene! Älä kalpene! Lämpene! Älä lämpene!
  • The VA-participle: kalpeneva, lämpenevä

Weak forms for verbtype 6:

I hope this article helps you navigate the jungle of astevaihtelu. There is a small number of exceptions that aren’t included in this article. I will be addressing these in a future article! For now, you’ll have to check out other sources for these.

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Marcin

Typo: 4.2: “disappears in the weak forms”

By the way, do the rules for consonant gradation for nouns apply also to adjectives? Some of the words that you mention here are actually adjectives (or at least more commonly used as adjectives than as nouns) such as hidas, vihreä, arvoton. I think the same rules apply also to numerals.

Inge (admin)

Adjectives and numbers as well, yes! The word “noun” in English is regularly used both as a synonym for “nomini” and “substantiivi”. “Nomini” covers any word that can be inflected in the grammatical cases (so adjectives and numerals are included). I unintentionally mix them too sometimes; normally I try to reserve the word “noun” for substantiivi only, and refrain from using “nominal” at all. There are enough grammar terms on my website already.

I added some small mentions of adjectives here and there into the article. Thank you for the feedback! 🙂