1   Introduction

The strong-grade plural stem is used to form the plural of cases that require a strong-grade stem. These cases include the genitive, partitive, essive, illative, and comitative. A good knowledge of consonant gradation and vowel change i ~ e is of great use.

2   Formation

The easiest way of forming the strong-grade plural stem is to form it from the general plural stem, if a word ends in a vowel, and form if from the essive stem, if a word ends in a consonant.

2.1   Words that end in a vowel

If a word ends in a vowel, the strong-grade plural stem is similar to the general plural stem, except for that it always takes the strong grade such as the nominative form. In the inflection examples below, the inessive and essive endings have been separated from the stem by a hyphen.

Nominative	Inessive pl	Essive pl	Translation
kova	kovi-ssa	kovi-na	hard
luuta	luudi-ssa	luuti-na	broom
ripa	rivoi-ssa	ripoi-na	handle
leuka	leuoi-ssa	leukoi-na	chin
jalka	jaloi-ssa	jalkoi-na	foot
mansikka	mansikoi-ssa	mansikkoi-na	strawberry
väärä	vääri-ssä	vääri-nä	wrong
kahvi	kahvei-ssa	kahvei-na	coffee
mäki	mäi-ssä	mäki-nä	hill
vesi	vesi-ssä	vesi-nä	water
kyky	kyvyi-ssä	kykyi-nä	ability
nalle	nallei-ssa	nallei-na	teddy bear
aatto	aatoi-ssa	aattoi-na	eve
maa	mai-ssa	mai-na	country
ehtoo	ehtoi-ssa	ehtoi-na	evening
suo	soi-ssa	soi-na	marsh
neliö	neliöi-ssä	neliöi-nä	square

2.2   Words that end in a consonant

If a word ends in a consonant or a relic consonant, the strong-grade plural stem is formed from the essive stem. In the inflection examples below, the essive endings have been separated from the stem by a hyphen.

a) Essive stem ends in -te

If the essive stem ends in -te, in front of which there is a vowel, the strong-grade plural stem is formed by replacing the te by ksi. This group includes only words whose nominative stem ends in -s.

Nominative	Essive sg	Essive pl	Translation
osuus	osuute-na	osuuksi-na	share, part
kauneus	kauneute-na	kauneuksi-na	beauty
rakkaus	rakkaute-na	rakkauksi-na	love
teollisuus	teollisuute-na	teollisuuksi-na	industry
hyvyys	hyvyyte-nä	hyvyyksi-nä	goodness

b) Essive stem ends in -nte

If the essive stem ends in -nte, the strong-grade plural stem is formed by replacing the nte by nsi. This group includes only words whose nominative stem ends in -s or -t.

Nominative	Essive sg	Essive pl	Translation
kolmas	kolmante-na	kolmansi-na	the third
neljäs	neljänte-nä	neljänsi-nä	the fourth
tuhannes	tuhannente-na	tuhannensi-na	the thousandth
mones	monente-na	monensi-na
tuhat	tuhante-na	tuhansi-na	thousand

c) Other words

The strong-grade plural stem of other words is formed by replacing the last letter of the essive stem by the plural marker i. Thus, the strong-grade plural stem is similar to the general plural stem.

Nominative	Essive sg	Essive pl	Translation
vene	venee-nä	venei-nä	boat
laite	laittee-na	laittei-na	device
koe	kokee-na	kokei-na	test
avain	avaime-na	avaimi-na	key
sydän	sydäme-nä	sydämi-nä	heart
tytär	tyttäre-nä	tyttäri-nä	daughter
sisar	sisare-na	sisari-na	sister
karvas	karvaa-na	karvai-na	bitter
paras	parhaa-na	parhai-na	the best
kiuas	kiukaa-na	kiukai-na	sauna heater
varis	varikse-na	variksi-na	crow
ohut	ohue-na	ohui-na	thin
neitsyt	neitsye-nä	neitsyi-nä	virgin

d) New loan words

The strong-grade plural stem of new loan words that end in a consonant is formed by replacing the last i of the essive stem by e and adding the plural marker i after it.

Nominative	Essive sg	Essive pl	Translation
stadion	stadioni-na	stadionei-na	stadium
radar	radari-na	radarei-na	radar

3   Usage

The strong-grade plural stem is used to form the plural of the genitive, partitive, essive, illative, and comitative. The following example shows, how case endings are attached to the strong-grade plural stem. Note that the plural marker i changes to j between vowels.

Case	Word	Translation
Nominative	jalka	foot
Genitive pl	jalkojen	of the feet
Partitive pl	jalkoja	(some) feet
Essive pl	jalkoina	as the feet
Illative pl	jalkoihin	into the feet
Comitative pl	jalkoineni	with my feet