Swedish noun plurals and definite forms

Swedish nouns form their plural in one of five ways, and the definite forms follow from them. This sounds like a lot, but the groups are fairly predictable once you know the gender. The key is to learn each new noun with its article and its plural, for example en bil, bilar or ett hus, hus. Start with en vs ett if you have not met the two genders yet.

The five plural groups

Group	Ending	Singular	Plural	Definite plural
1	-or	en flicka	flickor	flickorna
2	-ar	en bil	bilar	bilarna
3	-er	en student	studenter	studenterna
4	-n	ett äpple	äpplen	äpplena
5	none	ett hus	hus	husen

Group 1 (-or) is mostly en-words that end in -a: en flicka, en lampa, en kvinna.
Group 2 (-ar) is mostly other en-words, such as en pojke, en bil, en dag.
Group 3 (-er) has many loanwords and words ending in a consonant: en student, en katt, en bok (plural böcker, with a vowel change).
Group 4 (-n) is ett-words ending in a vowel: ett äpple, ett ställe, ett piano.
Group 5 (no ending) is ett-words ending in a consonant, and en-words for people that end in -are: ett hus, ett barn, en lärare, en arbetare.

The definite forms

The definite singular is the suffix you met in the gender guide (bilen, huset). The definite plural is built from the plural form:

Group	Definite plural ending	Example
1, 2, 3	-na	flickorna, bilarna, studenterna
4	-a	äpplena
5 (ett-words)	-en	husen, barnen
5 (en-words)	-na	lärarna

So the plural of a noun, with "the", reads de stora husen (the big houses). When an adjective comes before the noun, you still need both the article and the suffix.

Nouns with a vowel change

A small group of common nouns change their vowel in the plural, and you must learn them individually.

Singular	Plural	Meaning
en man	män	man, men
en bok	böcker	book, books
en bror	bröder	brother, brothers
en fot	fötter	foot, feet
ett land	länder	country, countries
en dotter	döttrar	daughter, daughters

Common mistakes

Using English -s. Bilars is wrong, and bilar is right. The letter s in Swedish marks possession or the passive, not a plural.
Adding a plural to ett-words with no plural ending. The plural of ett hus is hus, and husen is the definite plural. Only the context shows whether it is one house or several.
Forgetting the definite suffix. Barnen leker (the children are playing) needs -en.
Treating the plural of en bok as boker. The correct form is böcker.

A learning tip

Do not memorise the groups as abstract rules. Learn the plural with the noun. When you meet a new word, check a dictionary for the plural and add it to your list: en katt, katter, katten, katterna.

Practice

Now see how Swedish builds sentences in verb-second word order.