Irregular Dutch plurals: steden (cities), kinderen (children), and musea (museums)

De stad → de steden (the city → the cities) changes the vowel, so learn this plural together with the noun. Most Dutch nouns use -en or -s, but you cannot safely predict forms such as het kind → de kinderen (the child → the children) and het museum → de musea (the museum → the museums) from the singular alone.

Learn the vowel-changing and -eren forms on this page word by word. Learn each borrowed word with all of its accepted plural forms. The nouns in -heid follow one rule instead: the plural is -heden.

• An -en plural with a changed vowel: het schip → de schepen (the ship → the ships).
• The ending -eren: het ei → de eieren (the egg → the eggs).
• A plural kept from Latin that you learn with the word: de musicus → de musici (the musician → the musicians).
• A predictable ending, -heid → -heden: de mogelijkheid → de mogelijkheden (the possibility → the possibilities).

Het schip → de schepen (the ship → the ships) still adds -en, but the vowel in the singular changes. In several words a short vowel becomes long; in others the vowel itself changes. Open and closed syllables explains how to spell a long vowel once you know it is there. Spelling alone does not tell you which nouns change.

The i → e change also appears in de smid → de smeden (the smith → the smiths). Stad → steden is an exceptional a → e change. Do not copy the regular pattern de man → de mannen (the man → the men): stadden is not a word. Memorise the changed stem together with the noun.

De mogelijkheid → de mogelijkheden (the possibility → the possibilities) changes the ending itself: every noun ending in -heid replaces that ending with -heden, so you learn the whole group at once instead of word by word. The ending -heid also makes the noun a de-word.

Do not add -en to the singular: mogelijkheiden is not a word.

Meaning decides whether a noun in -heid needs a plural at all. Many nouns in -heid name a quality, and a quality rarely needs a plural. Use the plural where you count separate cases. De werkzaamheden are the tasks listed in a job description. De overheden are separate authorities: de gemeente (the municipality) and de provincie (the province).

Het kind → de kinderen (the child → the children) belongs to a small, fixed list of plurals in -eren. The singular does not show that a noun belongs to this list, so learn the whole pair. The common examples below take het in the singular. Like every Dutch plural, they use de in the plural.

Lammeren uses the short-vowel consonant-doubling rule: the double m keeps the a short. Kalveren uses the f/v spelling alternation: the final f in kalf returns as v before the ending; see the v/f and z/s spelling alternations. The ending -eren itself still has to be memorised.

Het museum → de musea (the museum → the museums) keeps a plural inherited from Latin. A singular ending such as -um narrows the possible plural forms, but it does not determine them. Many words in -um allow -a, sometimes alongside Dutch -s. Nouns for people ending in -icus usually have an -ici plural. Check and learn the accepted form or forms for each word.

Both musea/museums and centra/centrums are standard; for these two nouns, musea and centra are the more usual forms. Do not extend the pattern to every matching ending. Het album → de albums (the album → the albums), not alba. Het criterium (the criterion) has de criteria, not criteriums.

The ending -us is equally word-specific. Many other nouns take Dutch -ussen: de cursus → de cursussen (the course → the courses) and het virus → de virussen (the virus → the viruses). By contrast, use de musici, not de musicussen.

For these nouns, the meaning selects the accepted plural forms:

• Het been (the leg or bone) uses de benen when it means leg. When it means bone, both de benen and de beenderen are accepted. The form beenderen therefore points specifically to bones, while context tells you whether benen means legs or bones.
• Het blad (the tree leaf, sheet, or page) uses de bladeren or de bladen for a tree leaf. For other meanings, such as sheets, trays, or magazine issues, it uses de bladen.

Het pad (the path) and de pad (the toad) are two different nouns. The path forms de paden; the toad forms de padden.

Do not force a regular-looking form such as stadden or kinden, and do not invent a Latin plural from an ending alone. Double plurals such as musea's and medici's are also wrong: musea and medici are already plural. Learn each noun with its de or het article and its accepted plural or plurals.