Double or single vowel letters: maan (moon) and manen (moons)
Why maan (moon) uses two vowel letters but manen (moons) uses one — and where this regular Dutch spelling pattern stops.
Maan (moon) becomes manen (moons). The vowel sound stays the same, but its spelling changes from two vowel letters to one. A closed syllable ends in a consonant. An open syllable ends in a vowel. Usually, aa, ee, oo, and uu use two letters in a closed syllable and one in an open syllable. Final ee is the separate case explained below.
Let the syllable choose the spelling
Boom (tree) becomes bomen (trees) with the same vowel sound. The closed syllable in boom uses oo. The open first syllable in bo-men uses o.
| Condition | What to write | Examples |
|---|---|---|
| Long vowel sound in a closed syllable | Two vowel letters | maan (moon), steen (stone), boom (tree), muur (wall) |
| The same vowel sound in an open syllable | One vowel letter | ma-nen (moons), ste-nen (stones), bo-men (trees), mu-ren (walls) |
| Short stressed vowel in a regular form | One vowel letter; before an ending, double the following consonant to keep the syllable closed | man → mannen (man → men), bom → bommen (bomb → bombs), kat → katten (cat → cats), pen → pennen (pen → pens) |
Long and short are classroom labels for vowel groups. They do not count letters or merely tell you to hold one sound longer. Maan and man have different vowels. Maan and manen keep the same vowel.
The alternating rule covers aa/a, ee/e, oo/o, and uu/u. Other vowel spellings follow separate rules. For example, dier → dieren (animal → animals) keeps ie, boek → boeken (book → books) keeps oe, and deur → deuren (door → doors) keeps eu. Loanwords such as taxi (taxi) and bureau (desk) also fall outside this regular pattern. So do plurals that change vowel, such as dag → dagen (day → days) and schip → schepen (ship → ships). The open and closed syllable rule and syllable division explain how to find the boundary.
Keep final ee double
Zee (sea), twee (two), and thee (tea) end in the long e sound and keep ee. In regular native words, final single e usually represents a schwa, the unstressed vowel in de, ze, and je. The double spelling distinguishes the long e sound from that final schwa.
Zee → zeeën (sea → seas) keeps the base word's ee. An established loanword can do the same: idee → ideeën (idea → ideas). In both plurals, the trema on ë marks the start of a new syllable. Final a, o, and u do not need to double for a long sound, as na (after), zo (so), and nu (now) show.
Write manen and bomen, not maanen or boomen
Maan becomes ma-nen, so write manen, not maanen. Boom becomes bo-men, so write bomen, not boomen. In each open first syllable, one vowel letter represents the same sound that needed two letters in the closed singular. Split the word before you choose the spelling.
- Which spelling of the plural of *maan* (moon) is correct?
- *maanen*
- *manen*
- *mannen*
- *maenen*
The singular *maan* has a closed syllable, so its vowel sound uses *aa*. In *ma-nen*, that same sound is in an open syllable and uses one *a*: *manen*. *Mannen* is the plural of *man* and has a different, short vowel.
- Why is *boom* written with double *oo* but *bomen* with single *o*?
- *boom* has a closed syllable, so its vowel uses *oo*; *bo-men* starts with an open syllable, so the same vowel uses *o*
- because plurals lose a letter at random
- because the *o* is short in *bomen*
- because *boom* is an older word
*Boom* ends in a consonant, so the closed syllable uses *oo*. In *bo-men*, the *o* ends the first syllable. That open syllable uses one letter for the same vowel sound.
- Which letters spell the vowel sound in *dier* (animal)?
- *ii*
- *ie*
- *ih*
- *y*
*Dier* and *dieren* use *ie*. This spelling follows a separate rule from the *aa/a*, *ee/e*, *oo/o*, and *uu/u* alternation. Loanwords such as *taxi* can use *i*, so *ie* is not an absolute rule.
- Why does *zee* (sea) keep both *e* letters at the end of the word?
- a final single *e* usually represents schwa, as in *de*
- because *ee* is always a special vowel
- because it is a short vowel
- because it has no plural
In regular native words, a final single *e* usually represents schwa, as in *de*. Dutch writes the long final e sound as *ee*: *zee*, *twee*, *thee*.
- *Vul in: Eén muur, twee ___.* (Fill in: One wall, two walls.)
- *muuren*
- *muren*
- *murren*
- *meuren*
The vowel sound in *muur* stays the same in the plural. In *mu-ren*, it is in an open syllable, so one *u* is enough: *muren*.
Test yourself
Question 1 of 5
Which spelling of the plural of maan (moon) is correct?