Icelandic Irregular Nouns

Declensions of Icelandic irregular nouns

In Icelandic, some nouns follow a completely different declension pattern as the one you know. They take totally different forms and some are affected by I-shift. Here are the most common deviations, but this is by no means a full list:

	father
nominative	faðir
accusative	föður
dative	föður
genitive	föður

	fathers
nominative	feður
accusative	feður
dative	feðrum
genitive	feðra

	mother
nominative	móðir
accusative	móður
dative	móður
genitive	móður

	mothers
nominative	mæður
accusative	mæður
dative	mæðrum
genitive	mæðra

	tree
nominative	tré
accusative	tré
dative	tré
genitive	trés

	trees
nominative	tré
accusative	tré
dative	trjá(m)
genitive	trjá(a)

	cat
nominative	köttur
accusative	kött
dative	ketti
genitive	kattar

	cats
nominative	kettir
accusative	ketti
dative	köttum
genitive	katta

	book
nominative	bók
accusative	bók
dative	bók
genitive	bókar

	books
nominative	bækur
accusative	bækur
dative	bókum
genitive	bókar

The letters in parentheses are only added if the definite article is not being added.