Capitalization Rules

Greek capitalizes less than English in some places and exactly like English in others, and the trick is knowing which is which. Days and months stay capitalized, just as you already write them; the traps are elsewhere — in languages, nationality words, book titles, and the rules for where the stress accent (tonos) goes on a capital letter, including the words that open with a vowel digraph (Ευρώπη, Αίγυπτος, Αύγουστος), which almost every learner gets wrong.

What Greek capitalizes (mostly like English)

Greek treats several categories as proper nouns and writes them with an initial capital. If you have studied Spanish or French, notice that Greek does not follow those languages here.

Days of the week and months

Days and months are capitalized. This matches English and is the single most common thing learners "correct" by mistake after coming from Romance languages.

Holidays follow the same logic (Πάσχα, Χριστούγεννα). But an adjective derived from a day, month, or holiday drops back to lowercase: πασχαλινά αυγά ("Easter eggs"), χριστουγεννιάτικο δέντρο ("Christmas tree"). The name is a proper noun; the adjective is an ordinary word.

Proper names and the start of a sentence

Personal names, place names, and the first word of a sentence are capitalized, just as in English.

What Greek keeps lowercase (unlike English)

Here is where English speakers over-capitalize. Every category below is lowercase in Greek even though English writes it with a capital.

Languages

The name of a language is a common noun. Write it lowercase.

Nationality adjectives

When a nationality word describes something (acts as an adjective), it is lowercase.

But a nationality noun — a word naming a person of that nationality — is capitalized, because it behaves like a proper noun for a member of a people.

Seasons

The four seasons are lowercase (here Greek agrees with Spanish, and even with careful English style).

Titles of books, films and articles

English title-cases: The Old Man and the Sea, A Brief History of Time. The Greek orthographic norm is sentence case — a capital on the first word only, plus any proper noun inside it, every other word lowercase as in a running sentence.

• «Ο γέρος και η θάλασσα» — The Old Man and the Sea
• «Οι άθλιοι» — Les Misérables

You will still see publishers and Greek Wikipedia capitalize the content words — «Οι Άθλιοι», «Το Κόκκινο και το Μαύρο». What Greek never does is English's full title case, capitalizing the articles and conjunctions too. (Titles go in the guillemets « », where English uses italics or quotes.)

Titles before a name — and the pronoun εγώ

κύριος, κυρία, γιατρός, καθηγητής, πρόεδρος and the rest are ordinary common nouns, and they stay lowercase even when they stand right in front of a surname: ο κύριος Παπαδόπουλος, η κυρία Γεωργίου, ο γιατρός Νικολάου, ο πρόεδρος Παπαδάκης. English capitalizes the title along with the name ("Mr Papadopoulos", "Doctor Nikolaou"); Greek capitalizes only the name itself.

And one small mercy: Greek never capitalizes εγώ ("I") in mid-sentence. That capital I is an English quirk with no counterpart here — εγώ is written like any other pronoun.

The accent-on-capitals rule

This is the part that is genuinely Greek-specific, and it trips up learners who think capital letters never carry accents. Every polysyllabic Greek word takes exactly one tonos on its stressed syllable — and that does not change just because the letter is a capital.

An initial capital vowel keeps its tonos

When a word starts with a capital vowel and the stress falls on that first syllable, the tonos sits right on top of the capital: Ά, Έ, Ή, Ί, Ό, Ύ, Ώ.

Notice Έλληνας: the stress is on the first syllable (Έλ-λη-νας), so the capital Ε carries the tonos. Compare Ελλάδα: here the stress is on the second syllable (Ελ-λά-δα), so the capital Ε has no accent, and the tonos lands on the ά instead. The rule is not "capitals never take accents" — it is "the accent goes wherever the stress is, capital or not."

When the word begins with a vowel digraph

Greek writes some single vowels with two letters — αι, ει, οι, ου, αυ, ευ (the vowel digraphs) — and when one of them opens a word, two separate things need deciding. Keep them apart, because only the second one has anything to do with stress.

1. In a word with a single initial capital, only the first letter of the digraph is capitalized, and that holds regardless of where the stress falls. The second letter stays lowercase: it is not the start of the word, just the second half of a single vowel. So Ευρώπη (Europe), Αυστραλία (Australia), Ουκρανία (Ukraine), Αυστρία (Austria), Ουγγαρία (Hungary) — never ×ΕΥρώπη, ×ΑΥστραλία.

2. Where the tonos goes depends on the stress. If the stress falls on the digraph itself, the accent is written on the second vowel — which is the lowercase one — giving the lopsided but entirely correct Αίγυπτος (Egypt), Αύγουστος (August), Εύα (Eva), Ούτε ("Neither…", opening a sentence). If the stress falls later in the word, the digraph carries no mark at all and the tonos sits wherever the stress is: Ευ-ρώ-πη, Αυ-στρα-λί-α.

Two ways to get the stressed type wrong. Writing ×ΑΊγυπτος capitalizes both letters and leaves the rest of the word lowercase — a shape Greek never uses. Writing ×Αϊγυπτος is worse: that mark is a diaeresis, not an accent, and its whole job is to split a digraph into two separate vowels. Put it there and you have stopped writing Éyiptos and started writing a three-vowel word that does not exist.

ALL-CAPS text drops every accent

There is one big exception, and it is the opposite of the rule above. When a whole word or line is written in capital letters — headlines, signs, titles, logos — every tonos is omitted.

So the same city name appears two ways depending on the casing:

This is why Greek street signs and newspaper mastheads look accent-free: they are set in all-caps. Note the last two rows — the digraph words lose their tonos like everything else, so the lopsided Αί-/Αύ- shape simply disappears, and both letters of the digraph are now capitals (ΑΙΓΥΠΤΟΣ, ΑΥΓΟΥΣΤΟΣ). The "first letter only" rule above is about sentence case; in full caps everything is a capital.

…but the diaeresis survives

Here is the qualification that matters, and it is the reason to think of the two marks as different species. The tonos carries stress, which a reader can usually recover from context; the diaeresis carries syllable division, which they cannot. So uppercase drops the accent but keeps the diaeresis:

• προϊόν → ΠΡΟΪΟΝ (product — pro-i-ón, three syllables)
• καΐκι → ΚΑΪΚΙ (caique, fishing boat — ka-í-ki)
• πρωτεΐνη → ΠΡΩΤΕΪΝΗ (protein — pro-te-í-ni)

Look at πρωτεΐνη: the single letter ΐ was carrying both marks, and in caps exactly one of them survives. Strip the diaeresis and ΠΡΩΤΕΙΝΗ would be read pro-tí-ni, with ει as an ordinary digraph — a different word.

The four places English will mislead you

Days, months, seasons, personal names and the nationality noun all behave exactly as they do in English, so your instincts are safe there. These four are the ones to unlearn:

Common Mistakes

1. Capitalizing the language. This is transfer straight from English, where "Greek" and "English" are always capital.

2. Capitalizing the nationality adjective. As a describing word, it stays lowercase — even though the person noun is capitalized.

3. Lowercasing days and months. Learners coming from Spanish or French often drop these to lowercase. Standard Greek capitalizes them.

(You will see it in casual texting — but capitalizing also keeps την Τρίτη "on Tuesday" visibly apart from την τρίτη "the third one".)

4. Writing a tonos in ALL-CAPS text. Once the whole word is uppercase, the accent must come off.

5. Dropping the tonos from an initial capital vowel. A capital at the start of a word still carries the accent if the stress is there.

6. Title-casing a book or film title. Greek titles are sentence case: first word plus proper nouns, nothing else.

7. Capitalizing both letters of an initial digraph. Only the first letter goes capital; the tonos rides on the lowercase second one.

Key Takeaways

• Greek capitalizes days, months, holidays, proper names, nationality nouns, and sentence starts — the calendar and the people.
• Greek keeps languages, nationality adjectives, seasons, book titles and titles before a name (ο κύριος Παπαδόπουλος) lowercase — and never capitalizes εγώ.
• An initial capital vowel keeps its tonos where the stress falls (Έλληνας, Όχι). If the word opens with a vowel digraph, in a single-initial-capital word only the first letter is capitalized, stressed or not (Ευρώπη, Αυστραλία, Ουκρανία) — and when the stress is on the digraph, the tonos rides on the lowercase second letter: Αίγυπτος, Αύγουστος, Εύα (in full caps both letters go up: ΑΙΓΥΠΤΟΣ, ΑΥΓΟΥΣΤΟΣ).
• Fully uppercase text drops all accents (ΕΛΛΑΔΑ, ΑΘΗΝΑ, ΑΥΓΟΥΣΤΟΣ) — but the diaeresis stays (ΠΡΟΪΟΝ, ΚΑΪΚΙ), because it marks syllable division, not stress.