This masculine class is defined by a pair of endings: -ης in the singular, -ες in the plural. It is full of high-frequency human nouns — ο μαθητής (the student/pupil), ο ναύτης (the sailor), ο πολίτης (the citizen), ο εργάτης (the worker), ο κλέφτης (the thief) — plus a huge number of Greek family names (Παπαδάκης, Θεοδωράκης). The endings are tidy and regular; the three things to watch are the accent on the genitive plural, a rival plural in -ηδες that claims part of the class, and a look-alike adjective that declines nothing like these nouns.
The full paradigm
Take ο μαθητής ("the student"), an oxytone noun stressed on the final syllable:
| Case | Singular | Plural |
|---|---|---|
| Nominative | ο μαθητής | οι μαθητές |
| Genitive | του μαθητή | των μαθητών |
| Accusative | τον μαθητή | τους μαθητές |
| Vocative | μαθητή | μαθητές |
The endings are -ης / -η / -η / -η in the singular and -ες / -ών / -ες / -ες in the plural. As with every masculine class, the -ς only marks the nominative singular (μαθητής); the genitive, accusative and vocative singular are all the bare -η (μαθητή). Three of the four singular forms are therefore identical — a mercy for the learner.
Ο μαθητής που κάθεται μπροστά ρωτάει συνέχεια.
o mathitís pu káthete brostá rotái sinéchia
The student who sits at the front asks questions constantly.
Ο βαθμός του μαθητή ανέβηκε φέτος.
o vathmós tu mathití anévike fétos
The student's grade went up this year.
Οι μαθητές έχουν διακοπές τον Ιούλιο.
i mathités échun dhiakopés ton iúlio
The students are on holiday in July.
Accent: oxytone agents versus paroxytone nouns
Two accent types share this ending. Many are oxytone agent nouns in -τής — ο μαθητής, ο πωλητής (salesperson), ο αθλητής (athlete) — with the stress locked on the last syllable. Others are paroxytone, stressed on the next-to-last syllable: ο ναύτης, ο πολίτης, ο εργάτης, ο κλέφτης.
Where the difference bites is the genitive plural, which is regularly oxytone -ών for this whole class — even for the paroxytone nouns, whose accent therefore jumps to the ending:
- ο ναύτης → των ναυτών (not ×των ναύτων)
- ο εργάτης → των εργατών
- ο πολίτης → των πολιτών
For the already-oxytone μαθητής this is invisible (μαθητών keeps the stress on the end anyway), but for ναύτης and its kind the shift is real and audible.
Ο ναύτης έδεσε το σκοινί στον ντόκο.
o náftis édhese to skiní ston dóko
The sailor tied the rope to the dock.
Ο σύλλογος των μαθητών οργανώνει εκδρομή.
o síloghos ton mathitón orghanóni ekdhromí
The students' association is organising a trip.
Κάθε πολίτης έχει δικαίωμα ψήφου.
káthe polítis échi dhikéoma psífu
Every citizen has the right to vote.
Οι εργάτες σταμάτησαν για μεσημεριανό.
i erghátes stamátisan ya mesimerianó
The workers stopped for lunch.
The other -ης plural: -ηδες
Not every noun in -ης takes the plain -ες plural of μαθητής. A second, competing plural — -ηδες, with an extra -δ- syllable — covers two groups.
The first is family names. A large share of Greek surnames end in -ης — Παπαδάκης, Θεοδωράκης, Καζαντζάκης — and in the singular they decline exactly like μαθητής: του Παπαδάκη (of Papadakis), τον Παπαδάκη (I saw Papadakis). But when you mean the whole family ("the Papadakis family / the Papadakises"), the plural is -ηδες:
Οι Παπαδάκηδες μάς κάλεσαν για το Πάσχα.
i papadhákidhes mas kálesan ya to páscha
The Papadakis family invited us for Easter.
The second group is the important one to get right, because it is not a proper-name quirk at all: a large set of everyday, colloquial trade and household nouns in -ης takes exactly the same -ηδες plural.
- ο μπακάλης (grocer) → οι μπακάληδες
- ο χασάπης (butcher) → οι χασάπηδες
- ο μανάβης (greengrocer) → οι μανάβηδες
- ο νοικοκύρης (householder) → οι νοικοκύρηδες
- ο καφετζής (café owner) → οι καφετζήδες (informal)
What stays parisyllabic — plain -ες, the paradigm at the top of this page — is the learned layer of the class: the agent nouns in -της, ο μαθητής, ο ναύτης, ο πολίτης, ο εργάτης, ο αθλητής. So the split is by register and word-formation, not by the bare letters -ης: a bookish -της noun says οι μαθητές, while a colloquial trade word — very often built with the borrowed suffixes -τζής (from Turkish -cı: καφετζής, ταξιτζής) or -άρης (from Italian: ο βαρκάρης, boatman) — says οι καφετζήδες, οι βαρκάρηδες. Both ×οι χασάπες and ×οι μαθητήδες are wrong. The full four-class -δ- system is on Imparisyllabic masculines.
Οι χασάπηδες της αγοράς ανοίγουν από τις έξι το πρωί.
i chasápidhes tis aghorás aníghun apó tis éksi to proí
The butchers in the market open from six in the morning.
Πήγαινε στον μανάβη να πάρεις ντομάτες και αγγούρια.
píyene ston manávi na páris domátes ke angúria
Go to the greengrocer and get tomatoes and cucumbers.
The vocative in -η
To address a masculine -ης noun, use the bare -η — the same form as the genitive and accusative singular:
Γιάννη, σε ζητάνε στο τηλέφωνο.
yáni, se zitáne sto tiléfono
Giannis, someone's asking for you on the phone.
Παπαδόπουλε, σήκω στον πίνακα.
papadhópule, síko ston pínaka
Papadopoulos, come up to the board.
First names in -ης follow the same rule: Γιάννης → Γιάννη, Δημήτρης → Δημήτρη. Watch the ending, not the name: Χρήστος is a -ος name, so it is Χρήστο.
One asymmetry worth knowing, since it is exactly what the classroom example above shows. Surnames in -ος keep the older, fuller vocative in -ε (Παπαδόπουλος → Παπαδόπουλε, Καραγιάννης is -ης so Καραγιάννη), while first names in -ος take the colloquial -ο: Γιώργος → Γιώργο, Νίκος → Νίκο (not ×Γιώργε in ordinary speech). Address someone by surname and you are already in a slightly formal register, and the -ε ending goes with it.
Do not confuse the noun -ης with the adjective -ης
Here is the pitfall that even intermediate learners fall into. Greek also has a family of two-termination adjectives ending in -ης in the masculine and feminine and -ές in the neuter — διεθνής/διεθνής/διεθνές (international), ακριβής (precise), συνεχής (continuous). These look like our nouns in the nominative, but they descend from the Ancient Greek third declension and decline completely differently — their genitive is in -ούς, not -η:
- Noun: ο μαθητής → του μαθητή
- Adjective: ο διεθνής (αγώνας) → του διεθνούς (αγώνα)
So a "student's" is του μαθητή, but "of the international (match)" is του διεθνούς.
Ο διεθνής αερολιμένας της Αθήνας είναι πολύ μεγάλος.
o dhiethnís aeroliménas tis Athínas íne polí meghálos
The international airport of Athens is very large.
Common Mistakes
1. Keeping the -ς in the oblique singular. Genitive, accusative and vocative all use the bare -η.
❌ Ξέρω καλά τον μαθητής.
Incorrect — the accusative is τον μαθητή, without -ς.
✅ Ξέρω καλά τον μαθητή.
kséro kalá ton mathití
I know the student well.
2. Leaving the genitive plural stress in place. Paroxytone nouns move the accent to -ών.
❌ Η ζωή των ναύτων είναι δύσκολη.
Incorrect — the genitive plural is oxytone: των ναυτών.
✅ Η ζωή των ναυτών είναι δύσκολη.
i zoí ton naftón íne dhískoli
Sailors' lives are hard.
3. Giving a learned -της noun the -ηδες plural. The two plurals are not interchangeable.
❌ Οι μαθητήδες πέρασαν τις εξετάσεις.
Incorrect — μαθητής is a parisyllabic -της noun: its plural is μαθητές. The -ηδες plural belongs to surnames and colloquial trade nouns like μπακάληδες.
✅ Οι μαθητές πέρασαν τις εξετάσεις.
i mathités pérasan tis eksetásis
The students passed the exams.
4. Declining the adjective -ής like the noun. διεθνής is an adjective with genitive διεθνούς.
❌ Ο τελικός του διεθνή πρωταθλήματος.
Incorrect — the adjective's genitive is διεθνούς, not διεθνή.
✅ Ο τελικός του διεθνούς πρωταθλήματος.
o telikós tu dhiethnús protathlímatos
The final of the international championship.
Key Takeaways
- The class is singular -ης / plural -ες: endings -ης / -η / -η / -η (sg.) and -ες / -ών / -ες / -ες (pl.).
- The -ς marks only the nominative singular; genitive, accusative and vocative singular are the bare -η (μαθητή).
- The genitive plural is oxytone -ών for the whole class, so paroxytone nouns shift their accent: ναύτης → των ναυτών.
- Vocative singular is -η (Γιάννη!, μαθητή!). Surnames in -ος keep the -ε vocative (Παπαδόπουλε), while first names in -ος take -ο (Γιώργο).
- A rival plural in -ηδες covers family names (οι Παπαδάκηδες) and colloquial trade nouns (οι χασάπηδες, οι μπακάληδες, οι καφετζήδες). The learned agent nouns in -της are the ones that stay parisyllabic: οι μαθητές, οι ναύτες.
- Don't confuse this noun ending with the two-termination adjective in -ης (διεθνής), whose genitive is -ούς (διεθνούς).
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Start learning Greek →Related Topics
- The Vocative Case (Direct Address)A2 — How to change a noun's ending when you call or address someone: masculine φίλος → φίλε, but the name Γιώργος → Γιώργο; Γιάννης → Γιάννη; Θωμάς → Θωμά; feminine and neuter usually stay put (Μαρία!, παιδί μου!). The everyday address κύριε / κυρία and the dropped article.
- Two-Termination Adjectives in -ης / -ης / -εςB1 — The learned class where masculine and feminine share one form — ο/η διεθνής — and only the neuter differs (το διεθνές), with its distinctive -ούς genitive and -είς / -ή plural; common in news and academic Greek.
- Imparisyllabic Masculines (-άδες, -ούδες)B1 — A large family of masculine nouns — ο ψαράς, ο καφές, ο παππούς, ο μπακάλης — that grows an extra syllable in the plural (οι ψαράδες, οι καφέδες), a pattern English has almost nowhere.
- Masculine Nouns in -αςA2 — The two -ας masculine types: parisyllabic nouns like ο άντρας and ο πατέρας (plural -ες) versus imparisyllabic occupational nouns like ο ψαράς and ο παπάς (plural -άδες), with the genitive singular in bare -α that trips up learners.