Number

Icelandic nouns have two grammatical numbers: singular🇮🇸 eintala and plural🇮🇸 fleirtala:

• 1️⃣ Singular is used to talk about exactly one thing, for example einn hestur “one horse”. It’s also used for when using quantities ending in 1, for example tuttugu og einn hestur “21 horses”;
• 🔢 Plural is used for everything else.

Singular

The default or “dictionary” form of most nouns is the singular. As such, we won’t go into a discussion of how the singular is formed, because the singular is usually the first form of a noun you learn. See Gender for an overview of the singular endings.

Nouns that exist only in the singular

Certain nouns in Icelandic cannot be made grammatically plural, either because of their meaning or because a plural form simply doesn’t exist in the language. Some examples grouped by meaning:

Abstract nouns	athygli “attention”, skilningur “understanding”
Substances	grænmeti “vegetables”, málning “paint”, rafmagn “electricity”
Others	fé “livestock, money”, fólk “people”

Confusingly, the collective noun for “people”, fólk belongs to this group. Despite its meaning, it’s always grammatically singular. We can see this from the verb form and adjective ending it gets:

Fólk er heimskt!

Plural

Here we’ll deal with how to form the plural of nouns in the nominative case🇮🇸 nefnifall. See accusative, dative and genitive for explanations of how to form the plural in those cases.

Masculine

There are two main plural endings in the masculine. Depending on the singular ending, the plural form will be one of the following:

Singular endings	Plural ending	Singular		Plural
💪 Strong ‑ur  (⅔) ‑ir ‑ll ‑nn ‑Ø	‑ar	hestur læknir bíll, gaffall, spegill steinn foss, fugl, prófessor	→	hestar læknar bílar, gafflar, speglar steinar fossar, fuglar, prófessorar
🥀 Weak ‑i ‑a		penni, krakki herra		pennar, krakkar herrar
💪 Strong ‑ur  (⅓)	‑ir	staður, gestur, hvalur	→	staðir, gestir, hvalir

Some notes on these rules :

• The vast majority of strong masculine nouns get ‑ar in the plural. This includes all those that have ‑ir, ‑ll, ‑nn or no ending in the singular;
• Most strong masculine nouns ending in ‑ur get ‑ar in the plural as well. A large group get ‑ir though, probably around one-third or so (not an actual statistic). For these words, there’s no way to tell what the plural ending will be from the singular form, so you just have to learn that it’s one that gets ‑ir;
• All weak nouns, that is those ending in ‑i or ‑a in the singular, get ‑ar in the plural. The exceptions: a small group of nationality words listed below, which get ‑ir, and words ending in ‑andi.

note

Below we’ll go into detail on the quirks and exceptions of the masculine plural, but if you want to keep on learning the basic rules, skip straight to Feminine.

Nationality words

A small group of masculine weak nouns that describe nationalities get ‑ir in the plural instead of the expected ‑ar:

Singular	Plural
Ástrali, Dani, Grikki, Japani, Ítali, Tyrki	Ástralir, Danir, Grikkir, Japanir, Ítalir, Tyrkir

The forms Ástralar and Japanar also exist, but aren’t as common as the forms with ‑ir.

Words ending in ‑andi

Weak masculine nouns ending in ‑andi have an irregular plural ending, which is ‑endur:

Singular	Plural
nemandi, hlustandi, þýðandi	nemendur, hlustendur, þýðendur

Many of these words are occupations or groups of people. Another odd thing about this group is that the accusative plural is the same as the nominative plural.

Vowel changes

A few strong masculine nouns that get ‑ir in the plural undergo a vowel change known as I-shift:

Singular	Plural
þáttur, þráður	þættir, þræðir
björn, fjörður	birnir, firðir
ávöxtur, köttur, örn	ávextir, kettir, ernir

There aren’t many nouns in this group, but lots of them are extremely common. Learn more about the I-shift in masculine nouns.

Fully irregular plurals

There are always some, aren’t there? These masculine nouns follow their own sets of rules:

Rule	Singular	Plural
I-shift + ‑ur	bóndi, frændi bróðir, faðir fótur 🦶	bændur, frændur bræður, feður fætur
No change	fingur, vetur skór 👞	fingur, vetur skór
🤪	maður	menn

Maður has an very irregular declension overall. In the plural, it’s menn, but when you add the definite article it becomes mennirnir.

Feminine

There are three main plural endings in the feminine. Depending on the singular ending, the plural form will be one of the following:

Singular endings	Plural ending	Singular		Plural
💪 Strong ‑Ø	‑ir	rós, dós höfn, röð, öxl verslun	→	rósir, dósir hafnir, raðir, axlir verslanir
💪 Strong ‑Ø ‑i ‑ing	‑ar	grein, laug ermi, lygi æfing	→	greinar, laugar ermar, lygar æfingar
🥀 Weak ‑a	‑ur (+U-shift)	kona, króna, peysa kaka, tala	→	konur, krónur, peysur kökur, tölur

Some observations on the feminine plural:

• The vast majority of strong feminine nouns get ‑ir in the plural, but some get ‑ar, e.g. laug → laugar. You just have to learn these as exceptions;
• Strong feminine nouns that have ö in the stem get reverse U-shift in the plural, e.g. röð → raðir;
• Nouns ending in ‑un also get reverse U-shift in the plural, e.g. verslun → verslanir;
• All nouns ending in ‑ing get ‑ar in the plural, e.g. æfing → æfingar.

U-shift

Look out for U-shift in the feminine plural, it’s everywhere! It can work in either direction, so ö → a or a → ö. There’s nothing irregular about this, it’s a completely predictable process.

note

Below we’ll go into detail on the quirks and exceptions of the feminine plural, but if you want to keep on learning the basic rules, skip straight to Neuter.

j-insertion

A couple of strong feminine nouns that end in ‑l get a j before the plural ending:

Singular	Plural
il, skel	iljar, skeljar

Vowel changes

Quite a few commonly used feminine nouns get the I-shift in the plural. Most of the time, this means the plural ending will be ‑ur:

Singular	Plural
bók, nótt, rót	bækur, nætur, rætur
dóttir, móðir	dætur, mæður
hönd, strönd, önd	hendur, strendur, endur
tá, kló	tær, klær
brú	brýr
lús, mús	lýs, mýs

If the noun ends in the vowel affected by I-shift, the ending will be ‑r. Lús and mús are just weird exceptions.

Full a full list of nouns in this group and an explanation of the quirks, see I-shift.

Other strong nouns with ‑ur

Some other strong feminine nouns get ‑ur in the plural despite not having a vowel change:

Singular	Plural
geit, grind, kind, sæng	geitur, grindur, kindur, sængur
eik, steik	eikur, steikur
flík, tík, vík	flíkur, tíkur, víkur

As you can see, a lot of these end in ‑k.

Neuter

The neuter is pretty straightforward:

Singular endings	Plural ending	Singular		Plural
💪 Strong ‑Ø	‑Ø (+U-shift)	hús, skip, lauf, box land, barn hundrað, sumar belti, veski	→	hús, skip, lauf, box lönd, börn hundruð, sumur belti, veski
🥀 Weak ‑a	‑u	auga, eyra, hjarta	→	augu, eyru, hjörtu

Just a couple of things to point out:

• Strong neuter nouns don’t get an ending in the plural, however they might get a U-shift, e.g. barn → börn. If the a is not in the first syllable, it will normally become u, e.g. hundruð;
• Weak neuter nouns get ‑u in the plural. This u can cause a U-shift, e.g. hjarta → hjörtu.

Now let’s dig into some of the quirks of the neuter.

U-shift and compound words

In compound words, the first a in the head (the final word that makes up the compound) is treated as if it is the first a in the word. This means it becomes ö in the plural, and not u:

Singular	Plural
fé-lag, vín-glas, þorsk-flak	fé-lög, vín-glös, þorsk-flök

Here hyphens are used to separate the word parts, but compound words are normally written all as one word in Icelandic.

U-shift and loanwords

Words borrowed into Icelandic from other languages that fit into a neuter-like pattern will get the U-shift in the plural where applicable:

Singular	Plural
app, gas, glas, plan	öpp, gös, glös, plön

Often, if there are multiple a’s in a word, only the second one will be U-shifted and it will change to ö rather than u:

Singular	Plural
apparat, plakat, salat	apparöt, plaköt, salöt

Nouns that exist only in the plural

Certain nouns in Icelandic only exist in the plural. Many of them refer to things that come in pairs or sets, some of them are multi-day holidays, but others are plural for no obvious reason:

Pairs/sets	buxur “trousers”, dyr “doorway, set of doors”, föt “clothes”, gleraugu “glasses”, skæri “scissors”
Holidays	jól “Christmas”, páskar “Easter”
Others	aðstæður “circumstances”, bókmenntir “literature”, gögn “data”, göng “tunnel”, hægðir “faeces”, hjólbörur “wheelbarrow”, lok “end”, samtök “organisation”, tónleikar “concert”, réttindi “rights”, veiðar “hunting, fishing”