This category lists Swedish nouns whose plural is formed irregularly with respect to spelling. It includes the singulars of all Swedish nouns except those that:

• are symbols or letters and form their plural by adding -:n.

Example: Ett a, två a:n. One a, two a's.

• are nouns which form their plural by adding -ar, -er, -or, -n or -Ø*.

Example: En fisk, två fiskar. One fish, two fish(es).

En vän, två vänner**. One friend, two friend.

En flicka, två flickor***. One girl, two girls.

En fiskare, två fiskare. One fisherman, two fishermen.

Ett bord, två bord. One table, two tables.

Ett bi, två bin. One bee, two bees.

• are neuter nouns which have the singular form-else and get the plural ending -r.

Example: Ett fängelse, två fängelser. One prison, two prisons.

• are common, one-syllable nouns which end with a vowel and get the plural ending -r.

Example: En ko, två kor. One cow, two cows.

• are nouns which have the singular form -an and get rewritten as -ningar in plural.

Example: En ansökan, två ansökningar. One application, two applications.

• are nouns which have the singular form -um and get rewritten as -er in plural.

Example: Ett museum, två museer. One museum, two museums/musea.

Ett observatorium, två observatorier. One observatory, two observatories.

• are proper or uncountable nouns

For the plural forms themselves seeCategory:Swedish irregular plurals.

* no plural ending is added

** Swedish words overall rarely end in -mm or -nn but can easily have -mm- or -nn- in them and still be regular, what makes some nouns with an added consonant is the vowel sound which shift from a long to a short sound

*** Swedish nouns with the common gender that end with a vowel often get the vowel replaced by the plural ending

*