1   Introduction

The partitive stem is an important stem of nominals, infinitives and participles along with the genitive stem. The main difference between these stems lies in consonant gradation. The partitive stem takes the strong grade, when the genitive stem takes the weak one, and vice versa. The partitive stem is used to form the partitive singular and the genitive plural. Anyway, the genitive plural cannot be formed from the partitive stem of any word, but there are certain restrictions. The partitive stem is also used to form the essive stem. A good knowledge of the consonant gradation and also vowel change i ~ e is of great use.

2   Formation

The formation of the partitive stem is very complicated. The following rules show, how the partitive stem is formed from the nominative and sometimes also the genitive stem. In the examples, the partitive ending -a/-ä/-ta/-tä has been separated from the partitive stem by a hyphen.

2.1   Words that end in a vowel

a) Words that do not undergo vowel change i ~ e

If a word ends in a vowel and it does not undergo the vowel change i ~ e, the partitive stem is similar to the nominative stem. This rule also applies to words which are affected by the consonant gradation.

Nominative	Partitive	Translation
koira	koira-a	dog
nalle	nalle-a	teddy bear
kiivi	kiivi-ä	kiwi fruit
talo	talo-a	house
koulu	koulu-a	school
syy	syy-tä	reason
kylä	kylä-ä	village
yö	yö-tä	night
silta	silta-a	bridge
vihko	vihko-a	notebook

b) Words that undergo vowel change i ~ e

If a word undergoes the vowel change i ~ e, there are two ways of forming the partitive stem.

If a word ends in -hi, -li, -ni, or -ri, in front of which there is a vowel, the partitive stem is formed by removing the i.

Nominative	Partitive	Translation
jouhi	jouh-ta	horsehair
kieli	kiel-tä	language
pieni	pien-tä	small
saari	saar-ta	island

There are three exceptions to the rule. Note that the word veli also requires an additional j.

Nominative	Partitive	Translation
Louhi	Louhe-a	Louhi
sini	sine-ä	the blue
veli	velje-ä	brother

Note also that the following words require a back-vowel partitive ending that is against vowel harmony rules.

Nominative	Partitive	Translation
meri	mer-ta	sea
veri	ver-ta	blood

If a word ends in -si, in front of which there is a vowel, or in -lsi, -nsi, or -rsi, the partitive stem is formed by replacing the si by t.

Nominative	Partitive	Translation
vesi	vet-tä	water
kuusi	kuut-ta	six
kansi	kant-ta	lid
jälsi	jält-tä
virsi	virt-tä	hymn

Exceptions!
The partitive stem of jousi, kusi, and kuusi is formed by omitting the i.

Nominative	Partitive	Translation
jousi	jous-ta	bow
kusi	kus-ta	piss
kuusi	kuus-ta	spruce

If a word ends in -ksi, the partitive stem is formed either by replacing it by h or s, or by omitting the i. This group includes only four words.

Nominative	Partitive	Translation
yksi	yh-tä	one
kaksi	kah-ta	two
uksi	us-ta	door
suksi	sukse-a or sus-ta (old form)	ski

If a word ends in -psi or -tsi, the partitive stem is formed by replacing it by s. This group includes only four words.

Nominative	Partitive	Translation
hapsi	has-ta	hair
lapsi	las-ta	child
peitsi	peis-tä	lance
veitsi	veis-tä (veitse-ä)	knife

If a word ends in -mi, in front of which there is a vowel, the partitive stem is formed either by replacing the i by e, or the mi by n.

Nominative	Partitive	Translation
lumi	lun-ta	snow
nimi	nime-ä	name

If a word does not belong to any of the groups mentioned above, the partitive stem is formed by replacing i by e.

Nominative	Partitive	Translation
tammi	tamme-a	oak
saarni	saarne-a	ash
tähti	tähte-ä	star
kurki	kurke-a	crane

c) Comparative forms

The partitive stem of comparative forms is formed by replacing the comparative ending -mpi by mpa.

Nominative	Partitive	Translation
suurempi	suurempa-a	bigger
isompi	isompa-a	bigger
kauniimpi	kauniimpa-a	nicer

2.2 Words that end in a consonant

There are only five consonants, l, n, r, s, and t, which a Finnish word can end in. Loan words can end in any consonant.

a) Words that end in a relic consonant

If a word ends in a relic consonant, the partitive stem is formed by adding t to the nominative stem. Actually, this t is the relic consonant which becomes visible now.

Nominative	Partitive	Translation
vene	venet-tä	boat
koe	koet-ta	test
laite	laitet-ta	device

b) Words that end in s

If a word ends in s, the partitive stem is formed with the aid of the genitive stem.

If the genitive stem ends in -kse, -he, or a long vowel, the partitive stem is similar to the nominative stem.

Nominative	Genitive	Partitive	Translation
varis	varikse-n	varis-ta	crow
hius	hiukse-n	hius-ta	hair
tulos	tulokse-n	tulos-ta	result
kynnys	kynnykse-n	kynnys-tä	treshold
väärennös	väärennökse-n	väärennös-tä	forgery
karvas	karvaa-n	karvas-ta	bitter
tehdas	tehtaa-n	tehdas-ta	factory
varvas	varpaa-n	varvas-ta	toe
kiuas	kiukaa-n	kiuas-ta	sauna heater
kirves	kirvee-n	kirves-tä	ax
tiivis	tiivii-n	tiivis-tä	compact
uros	uroo-n	uros-ta	male
räystäs	räystää-n	räystäs-tä	eaves
paras	parhaa-n	paras-ta	the best
mies	miehe-n	mies-tä	man

If the genitive stem ends in -de or -nne, the partitive stem is formed from the nominative stem by replacing the s by t.

Nominative	Genitive	Partitive	Translation
osuus	osuude-n	osuut-ta	share, part
kauneus	kauneude-n	kauneut-ta	beauty
rakkaus	rakkaude-n	rakkaut-ta	love
teollisuus	teollisuude-n	teollisuut-ta	industry
hyvyys	hyvyyde-n	hyvyyt-tä	goodness
kolmas	kolmanne-n	kolmat-ta	the third
neljäs	neljänne-n	neljät-tä	the fourth
tuhannes	tuhannenne-n	tuhannet-ta	the thousandth
mones	monenne-n	monet-ta

c) Words that end in n

If a word ends in -nen, the partitive stem is formed by replacing the nen by s.

Nominative	Partitive	Translation
hevonen	hevos-ta	horse
ihminen	ihmis-tä	person
puinen	puis-ta	wooden

There are two ways of forming the partitive stem of superlative forms. This group also includes the word vasen 'left'. The easiest way of forming the partitive stem is to use the stem similar to the nominative stem.

Nominative	Partitive	Translation
suurin	suurin-ta	the biggest
isoin	isoin-ta	the biggest
vasen	vasen-ta	left

The partitive stem can also be formed by replacing the superlative ending -n by mpa.

Nominative	Partitive	Translation
suurin	suurimpa-a	the biggest
isoin	isoimpa-a	the biggest
vasen	vasempa-a	left

The partitive stem of other words, which end in -n, is similar to the nominative stem.

Nominative	Partitive	Translation
avain	avain-ta	key
sydän	sydän-tä	heart
sadin	sadin-ta	trap
hapan	hapan-ta	sour
otin	otin-ta	handle
lämmin	lämmin-tä	warm
ien	ien-tä	gum
joutsen	joutsen-ta	swan
mahdoton	mahdoton-ta	impossible
työtön	työtön-tä	unemployed

The partitive stem of the numbers 7 - 10 and 17 - 19 is formed by omitting the n.

Nominative	Partitive	Translation
seitsemän	seitsemä-ä	seven
kahdeksan	kahdeksa-a	eight
yhdeksän	yhdeksä-ä	nine
kymmenen	kymmenen-tä	ten
seitsemäntoista	seitsemä-ä-toista	seventeen
kahdeksantoista	kahdeksa-a-toista	eighteen
yhdeksäntoista	yhdeksä-ä-toista	nineteen

d) Words that end in l

If a word ends in l, the partitive stem is similar to the nominative stem. This group includes about ten words.

Nominative	Partitive	Translation
askel	askel-ta	step
kannel	kannel-ta	kantele
kyynel	kyynel-tä	tear
sävel	sävel-tä	note, melody
sammal	sammal-ta	moss
ommel	ommel-ta	stitch
taival	taival-ta	trip
nivel	nivel-tä	joint
vemmel	vemmel-tä
petkel	petkel-tä	sprudder, stamper

e) Words that end in r

If a word ends in r, the partitive stem is similar to the nominative stem.

Nominative	Partitive	Translation
tatar	tatar-ta	knotweed (Polygonum)
tytär	tytär-tä	daughter
sisar	sisar-ta	sister

f) Words that end in t

If a word ends in t, the partitive stem is similar to the nominative stem. This group also includes past participle active tenses.

Nominative	Partitive	Translation
kevät	kevät-tä	spring
tuhat	tuhat-ta	thousand
ohut	ohut-ta	thin
olut	olut-ta	beer
lyhyt	lyhyt-tä	short
neitsyt	neitsyt-tä	virgin
kätkyt	kätkyt-tä	cradle
airut	airut-ta	harbinger
kevyt	kevyt-tä	light
ehyt	ehyt-tä	whole
tiehyt	tiehyt-tä	duct
pehmyt	pehmyt-tä	soft
ainut	ainut-ta	only
juossut	juossut-ta	run
laulanut	laulanut-ta	sung
syönyt	syönyt-tä	eaten
vienyt	vienyt-tä	taken

g) Loan words

The partitive stem of new loan words, which end in a consonant, is formed simply by adding a vowel i to the nominative stem. Foreign proper nouns belong to this group as well. This rule also applies to words that end in the consonants l, n, r, s, and t.

Nominative	Partitive	Translation
rock	rocki-a	rock music
radar	radari-a	radar
Internet	Interneti-ä	Internet
Linux	Linuxi-a	Linux
Windows	Windowsi-a	Windows
New York	New Yorki-a	New York

3   Usage

The partitive stem is used to form the partitive singular and sometimes the genitive plural as well.

The partitive ending -a/-ä is added to a stem which ends in a single vowel, and the ending -ta/-tä to a stem which ends in a long vowel, a diphthong, or a consonant.

The genitive plural ending -ten can be added only to a word whose partitive stem ends in a consonant, excluding some exceptions. (For further information, see the page on forming the genitive plural.)

The following example shows, how case endings are attached to the partitive stem.

Case	Word	Translation
Nominative sg	kieli	language
Partitive sg	kieltä	language
Genitive pl	kielten	of the languages
Nominative sg	jalka	foot
Partitive sg	jalkaa	foot