Capitalization and the Capital IJ

English capitalises generously: days, months, languages, nationalities, the pronoun I, and the first word of almost everything. Dutch is far more sparing — and where it does capitalise, it has one rule that surprises every learner and breaks half the world's spellcheckers: when a word starting with the digraph ij takes a capital, both letters go up. IJsland, not Ijsland. This page covers what Dutch capitalises, what it pointedly does not, and that one famous exception.

What Dutch does NOT capitalise

Start with the things English speakers reflexively capitalise and Dutch does not. Each of these is a real transfer error, so it's worth seeing them up front.

The pronoun ik ("I"). Dutch never capitalises it mid-sentence. English is actually the odd language out here — almost no other language capitalises its word for "I."

Days of the week and months. Always lowercase: maandag, dinsdag, woensdag... januari, februari, maart, april.

(But not languages or nationalities.) English speakers often assume Dutch lowercases these the way it lowercases days and months. It does not — Nederlands, Frans, and the adjectives Nederlandse, Franse all keep their capital. Because this is the opposite of what learners expect, it gets its own section right below.

The languages and nationalities rule (read carefully)

Here is the rule learners most often get wrong, usually because a textbook oversimplified it: anything still pointing at a real country, region or place keeps its capital — noun and adjective.

• The language as a noun is capitalised: het Nederlands, het Engels, het Duits.
• The country and people names are capitalised: Nederland, de Nederlanders, een Belg.
• And the geographic adjective is also capitalised: een Nederlandse film, de Belgische kust, Franse wijn, een Duitse auto.

In other words, Dutch agrees with English here more than you'd expect: Franse kaas is capitalised exactly as "French cheese" is.

Both forms of "Dutch" here take a capital: Nederlandse (the adjective describing film) and Nederlands (the language as a noun). The only thing Dutch lowercases that English capitalises is days, months, and "I" — not nationalities.

The lowercase cases are the ones where the geographic link has faded and the word has become a generic label:

• Figurative idioms where the place is no longer meant: een franse slag (a sloppy, rushed job — nothing French about it), russisch roulette. Contrast the real event de Olympische Spelen (capital, a proper name) with the figurative een olympische gedachte ("an Olympic spirit", lowercase).
• Product and variety names that started as places but now name a type: een glas bordeaux (the wine), jonge gouda (the cheese, versus the city Gouda).

What Dutch DOES capitalise

Beyond the obvious sentence-initial capital, Dutch capitalises:

Proper nouns — names of people, countries, cities, brands, institutions: Amsterdam, Anna, Nederland, de Rijksuniversiteit, Albert Heijn.

The polite U in religious and very formal contexts. In ordinary writing the polite pronoun is lowercase u. But when addressing God in prayer, or in highly deferential formal correspondence, you'll see capital U (and Uw). This is a register marker, not an everyday rule.

Both words in a multi-word proper name. In the official name of an event or historical period, the descriptive word is capitalised too: de Olympische Spelen, de Tweede Wereldoorlog, de Gouden Eeuw. Used figuratively, outside that fixed name, the same adjective drops to lowercase: een olympische gedachte ("an Olympic spirit"). (Ordinary nationality adjectives such as Franse and Nederlandse are already covered above — they keep their capital regardless.)

The capital IJ: both letters go up

Now the headline rule. Dutch treats ij as a single sound and, historically, a single letter — the lange ij. When such a word begins a sentence or is a proper noun, you capitalise the whole digraph, not just the i:

Why both letters? Because ij is one indivisible unit — a digraph that Dutch treats almost like a single letter (it even has its own key on old Dutch typewriters and its own slot in some alphabets). You capitalise a letter as a whole; you don't capitalise "half" of it. This is the same logic that makes ij indivisible when you split a word across a line. Capitalising only the I would be like writing "tHe" — splitting something that belongs together.

Crucially, this applies only to the digraph ij (the lange ij), not to the separate vowels i + j that happen to sit side by side in some loanwords. In a word like bijou, where the i and j belong to different syllables, normal capitalisation applies. But for native Dutch ij — the overwhelming majority of cases — both letters rise together.

Common Mistakes

The errors below are almost all direct imports of English habits — capitalising what English capitalises — plus the one uniquely Dutch IJ trap.

Key Takeaways

• Default to lowercase. Dutch capitalises far less than English.
• Lowercase: ik, days (maandag), and months (april) — and a nationality adjective only when it has gone figurative (een franse slag = a sloppy job).
• Capital: proper nouns (Amsterdam, België), language nouns (het Nederlands, Frans), geographic adjectives (Nederlandse, Franse, Belgische), and the polite U only in religious/very formal address.
• The IJ rule: when a word starting with the digraph ij is capitalised, both letters go up — IJsland, IJssel, IJmuiden — never Ijsland. The ij is one indivisible unit, which is also why it's never split across a line.