Stress and the Tonos (´)

If you learn only one diacritic in Greek, learn this one. The small forward-leaning stroke over a vowel — καλημέρα, νερό, άνθρωπος — is the tonos (τόνος, "accent"), and it does one job with total consistency: it marks the stressed syllable of the word. Unlike the accents of French or Spanish, the Greek tonos is not optional decoration and it is not about vowel quality. It tells you, unambiguously, which syllable to hit hardest. Because Greek stress is unpredictable and meaning-bearing, getting it wrong doesn't just sound off — it can produce a different word entirely.

One acute accent, on the stressed vowel

Every Greek word of two or more syllables carries exactly one tonos, written over the vowel of the syllable you stress. That's the whole rule of placement: find the beat, put the mark on its vowel.

Say kaliMÉra, neRÓ, ÁNthropos, paraKALÓ. In the romanization used throughout this guide, that same acute mark rides the stressed vowel for exactly this reason — Greek stress can't be guessed, so it must be shown.

The monotonic system: one accent, and never the old marks

Modern Greek uses the monotonic ("single-accent") system, made official in 1982. The rules are refreshingly strict:

• One accent per word, and it is always the acute (´).
• There are no grave accents, no circumflexes, and no breathing marks.

You may have seen older Greek books, church texts, or shop signs bristling with extra marks — a backward stroke here, a little curl or a comma-shape floating over an initial vowel there. That is the polytonic system, which distinguished acute/grave/circumflex accents and two "breathings" inherited from ancient pronunciation. By 1982 those distinctions had been silent for well over a millennium, so Greece abolished them for everyday writing. Modern Greek that you read, type, and are taught uses only the single acute tonos. (The story of those abandoned marks is on the history of the breathing marks.)

Stress is meaning-bearing

Here is why the mark is not a nicety. Greek has many pairs of words spelled with the same letters and told apart only by where the stress falls. Move the tonos and you change the word.

πότε vs ποτέ is the pair you'll trip over first, because both are everyday words and they differ by a single millimetre of ink. Read the accent every time.

Monosyllables: usually bare, with a few exceptions

Single-syllable words normally take no accent — there's only one syllable, so there's nothing to disambiguate: ναι (yes), δεν (not), το (the), και (and), μια (a). But a handful of one-syllable words do carry a tonos, purely to tell them apart from an identical-looking word:

• ή (or) vs η (the, feminine)
• πού (where?) vs που (that / who, relative)
• πώς (how?) vs πως (that, conjunction)

The accented πού and πώς ask a question; the bare που and πως link clauses. Same sound, different job — the accent is the only signal. This particular pair gets its own treatment on πού vs που.

Where does the stress land? The three-syllable window

You cannot predict which syllable a given word stresses — that is lexical, learned word by word. But there is one hard boundary that always holds: Greek stress falls on one of the last three syllables — the last, the second-to-last, or the third-to-last — and never further back. Linguists call this the "three-syllable window" or law of limitation.

• Last syllable: νερό (ne-RÓ), καλός (ka-LÓS)
• Second-to-last: καλημέρα (kali-MÉ-ra), σπίτι (SPÍ-ti)
• Third-to-last: άνθρωπος (ÁN-thro-pos), θάλασσα (THÁ-la-sa)

This won't tell you where the stress is, but it usefully tells you where it can't be: never on the fourth syllable from the end.

One honest complication: the second accent

The "one accent per word" rule has a single tidy exception you'll meet soon. When a word stressed on its third-from-last syllable is followed by a small unstressed pronoun (μου, σου, της…), the word gains a second tonos on its last syllable to keep the rhythm legal: το όνομα → το όνομά μου ("my name"), ο δάσκαλος → ο δάσκαλός μας ("our teacher"). It looks like a rule-breaker, but it's fully regular, and it's the only time a Greek word shows two accents. Don't worry about producing it yet — just don't be startled when you see όνομά.

Common Mistakes

1. Dropping the tonos when writing. An unaccented polysyllable is a spelling error, and can be ambiguous.

2. Stressing the wrong syllable and making a different word. ποτέ (never) is not πότε (when).

3. Adding old polytonic marks. No circumflexes, no breathings in Modern Greek — only the acute.

4. Accenting a monosyllable that shouldn't be. ναι, δεν, το take no accent; only the disambiguating handful (ή, πού, πώς) do.

Key Takeaways

• The tonos (´) marks the stressed syllable; every polysyllabic word carries exactly one, on the stressed vowel.
• Greek uses the monotonic system (since 1982): only the acute — never graves, circumflexes, or breathing marks (those are archaic polytonic).
• Stress is meaning-bearing: πότε/ποτέ, νόμος/νομός, γέρος/γερός differ only by accent placement.
• Monosyllables are bare except a few disambiguating pairs — ή/η, πού/που, πώς/πως (see πού vs που).
• Stress falls within the last three syllables and is unpredictable — learn each word with its accent. More patterns on the stress rules page.