When Dutch compounds need a hyphen

Dutch normally writes a compound as one word: school + plein → schoolplein (school playground). A hyphen, called a koppelteken in Dutch, marks a boundary only when a spelling rule requires it or when an extra boundary makes a difficult compound easier to read.

Write a hyphen at the join when the two parts would create a misleading vowel combination, when a letter-like element needs a visible boundary, or when one of the fixed name or prefix rules below applies.

1. First check that the parts form one compound. If no hyphen rule applies, join them: zorg + verzekering → zorgverzekering (health insurance).
2. Look at the join between the parts. Separate a vowel collision with a hyphen: foto-expositie (photo exhibition).
3. Check for an abbreviation, a loose letter, a number, or a symbol. Put a hyphen between that element and the word: tv-programma (TV programme).
4. Keep the hyphen in a compound geographical name, a name beginning with Sint, and the fixed prefix-like forms in the table.

The first two rules explain many forms on letters and signs: 65+-regeling (scheme for people aged 65 and over), mini-enquête (mini survey), and niet-Nederlandstalig (non-Dutch-speaking). Use the apostrophe rules for an ending added to an abbreviation instead: compare the compound sms-bericht with the verb sms'en.

A compound that has no mandatory hyphen may still take one where it helps the reader see the parts. Both stropop and stro-pop are correct; the second spelling shows stro + pop immediately.

• Use this optional hyphen sparingly. meerjarenonderhoudsplan is correct, and meerjaren-onderhoudsplan is also possible when the boundary helps your reader.
• An optional hyphen does not make spaces acceptable. Write one compound, with at most a hyphen inside it: Rabobankpand or Rabobank-pand, not Rabobank pand.
• A required hyphen stays required even in a longer compound: foto-expositieruimte keeps the hyphen that prevents the vowel collision.

A weglatingsstreepje (omission hyphen) marks the place where part of a compound has been left out to avoid repetition. Expand the phrase before deciding: land- en tuinbouw stands for landbouw en tuinbouw, so the missing word part bouw leaves a hyphen after land.

Use no hyphen when a whole free-standing word is omitted. Middelbaar en basisonderwijs is short for middelbaar onderwijs en basisonderwijs. The missing item is the separate word onderwijs after middelbaar, not part of a compound, so middelbaar- would be wrong.

• Do not replace the hyphen with a space: write tv-programma, not tv programma.
• Use a hyphen for a vowel collision inside a compound, but a trema inside an unbroken word or derivation: zee-egel but ideeën.
• Do not add an omission hyphen merely because a word is understood. First expand the phrase and check whether the missing item is part of one written compound.

Start with compound nouns and linking letters. Compare the trema, capital letters, and the apostrophe when another spelling boundary is involved.