In English, a noun phrase has exactly one word that can change shape: the noun, and only for plural. The good man → the good men; the stays the, good stays good. Greek is built on the opposite principle. Every word inside a noun phrase carries the same gender, number and case, and every one of them changes to show it. Ο καλός άνθρωπος becomes του καλού ανθρώπου becomes τον καλό άνθρωπο — three words moving together, every time. This is called concord, and it is the single structural habit you have to build to speak Greek at all.
One phrase, declined as a unit
Here is a complete noun phrase — article + adjective + noun — taken through all four cases in both numbers. Read it down the column, not across: what you are training is the reflex of changing all three words at once.
| Case | Singular | Plural |
|---|---|---|
| Nominative | ο καλός άνθρωπος | οι καλοί άνθρωποι |
| Genitive | του καλού ανθρώπου | των καλών ανθρώπων |
| Accusative | τον καλό άνθρωπο | τους καλούς ανθρώπους |
| Vocative | — καλέ άνθρωπε | — καλοί άνθρωποι |
Notice that in the genitive singular the accent moves on the noun: άνθρωπος → ανθρώπου. That is a separate rule about where Greek allows stress to sit, not part of agreement, and it is set out on Accent shift in nouns. But it is worth meeting here, because it means "declining a phrase" sometimes involves more than swapping a final letter.
Ο νέος διευθυντής άλλαξε τα πάντα μέσα σε έναν μήνα.
o néos dhiefthindís álakse ta pánda mésa se énan mína
The new director changed everything within a month.
Το γραφείο του νέου διευθυντή είναι στον τρίτο όροφο.
to ghrafío tu néu dhiefthindí íne ston tríto órofo
The new director's office is on the third floor.
Γνώρισα τον νέο διευθυντή στο ασανσέρ και δεν τον αναγνώρισα.
ghnórisa ton néo dhiefthindí sto asansér ke dhen ton anaghnórisa
I met the new director in the lift and didn't recognise him.
Three sentences, one phrase, three shapes. In English the new director would be identical in all three.
The endings do not have to match
This trips up learners who have learned agreement as "make the words rhyme". They rhyme in του καλού ανθρώπου, and that is a coincidence of the -ος declension. Change the noun class and the three words agree perfectly while looking nothing like each other.
| Phrase | Nominative | Genitive | Accusative |
|---|---|---|---|
| masc. -ης noun | ο καλός μαθητής | του καλού μαθητή | τον καλό μαθητή |
| fem. -η noun | η μεγάλη πόλη | της μεγάλης πόλης | τη μεγάλη πόλη |
| neut. -μα noun | το μεγάλο πρόβλημα | του μεγάλου προβλήματος | το μεγάλο πρόβλημα |
| fem. -ος noun | η γνωστή δημοσιογράφος | της γνωστής δημοσιογράφου | τη γνωστή δημοσιογράφο |
Του μεγάλου προβλήματος is a genitive twice over — -ου on the adjective, -ος on the noun. The endings are unrelated in shape; they are related in grammatical value. Agreement in Greek is agreement in case, gender and number, not in letters.
Το μεγάλο πρόβλημα είναι το πάρκινγκ, όχι το νοίκι.
to meghálo próvlima íne to párking, óchi to níki
The big problem is the parking, not the rent.
Το κόστος του μεγάλου έργου ξεπέρασε τα δύο εκατομμύρια.
to kóstos tu meghálu érghu ksepérase ta dhío ekatomíria
The cost of the big project went over two million. (journalistic)
Η γνωστή δημοσιογράφος έγραψε ένα άρθρο για το θέμα την περασμένη Κυριακή.
i ghností dhimosioghráfos éghrapse éna árthro ya to théma tin perazméni Kiriakí
The well-known journalist wrote an article about it last Sunday.
That last one is worth a second look. Δημοσιογράφος ends in -ος but is feminine when it refers to a woman, so the article and the adjective go feminine — η γνωστή — while the noun keeps its masculine-looking ending. The adjective follows the noun's gender, not its appearance. A whole family of professional nouns behaves this way (η γιατρός, η δικηγόρος, η υπουργός); see Feminine nouns in -ος.
The article does most of the visible work
You do not have to hold the whole system in your head at once, because one member of the phrase is always reliable. The definite article distinguishes every case unambiguously except in the neuter, which is why Greek nouns are learned with their article and why the article is the first thing a reader's eye lands on. The complete three-gender grid is laid out on How cases show on the article — learn it there, and the rest of the phrase becomes a matter of copying a value you have already decided.
Η καινούργια δουλειά της είναι πιο κοντά στο σπίτι.
i kenúrya dhuliá tis íne pio kondá sto spíti
Her new job is closer to home.
Της μικρής μου αδερφής της αρέσει πολύ το μπάσκετ.
tis mikrís mu adherfís tis arési polí to básket
My little sister really likes basketball.
Everything in the phrase joins in — except the possessive
Concord is not limited to one adjective. Demonstratives, quantifiers, numerals and stacked adjectives all take the same case, gender and number as the noun.
Όλα αυτά τα παλιά βιβλία πάνε για πέταμα.
óla aftá ta paliá vivlía páne ya pétama
All these old books are going in the bin.
Πούλησαν και τα δύο μικρά διαμερίσματα μέσα σε μια βδομάδα.
púlisan ke ta dhío mikrá dhiamerízmata mésa se mia vdhomádha
They sold both of the small flats within a week.
The rules for stacking several determiners in front of one noun are on Combining determiners, and the way numerals interact with case is on Case with numbers.
There is exactly one member of the phrase that never changes: the possessive clitic μου, σου, του, της, μας, σας, τους. It is already a genitive, frozen, and it does not care what case the phrase around it is in.
| Case of the phrase | Greek |
|---|---|
| Nominative | ο καλός μου φίλος |
| Genitive | του καλού μου φίλου |
| Accusative | τον καλό μου φίλο |
Πήγα στον γάμο του καλού μου φίλου του Στέλιου.
pígha ston ghámo tu kalú mu fílu tu Stéliu
I went to my good friend Stelios's wedding.
What concord buys you
Agreement looks like extra work, and at first it is. What it pays for is word-order freedom. Because τον καλό δικηγόρο is marked as an object no matter where it sits, Greek can move it to the front for emphasis, park an adverb between the article and the noun, or split the phrase across the sentence, and nothing is lost. English cannot do any of this, because its word order is its grammar.
Τον καλό δικηγόρο τον βρίσκεις μόνο με σύσταση.
ton kaló dhikighóro ton vrískis móno me sístasi
A good lawyer is something you only find through a recommendation.
Μεγάλη ζημιά δεν έπαθε το αυτοκίνητο, ευτυχώς.
megháli zimiá dhen épathe to aftokínito, eftichós
The car didn't take much damage, thankfully.
In both sentences a noun phrase has been fronted for emphasis and the case marking is the only thing keeping the grammar straight. Take the concord away and the sentences collapse into ambiguity — which is exactly what happens with neuter phrases, where nominative and accusative are identical and Greek quietly falls back on ordinary word order.
Vocative agrees too
When you address someone, the whole phrase goes into the vocative, adjective included. This is most visible in the opening line of a letter or email.
Αγαπητέ κύριε Παπαδόπουλε, σας ευχαριστώ για την απάντησή σας.
aghapité kírie Papadhópule, sas efcharistó ya tin apándisí sas
Dear Mr Papadopoulos, thank you for your reply. (formal)
Καλή μου Ελένη, χρόνια πολλά και να τα εκατοστίσεις!
kalí mu Eléni, chrónia polá ke na ta ekatostísis
My dear Eleni, happy birthday and many happy returns! (informal)
Common Mistakes
1. Inflecting the noun but leaving the adjective in its dictionary form. The commonest agreement error of all, and it is audible immediately.
❌ Γνώρισα τον καινούργιος γείτονα χθες.
Incorrect — the adjective must be accusative too: τον καινούργιο γείτονα.
✅ Γνώρισα τον καινούργιο γείτονα χθες στο ασανσέρ.
ghnórisa ton kenúryo yítona chthes sto asansér
I met the new neighbour in the lift yesterday.
2. Agreeing with the ending instead of the gender. Nouns like μέθοδος and είσοδος end in -ος and are feminine.
❌ Ο νέος μέθοδος δεν δούλεψε καθόλου.
Incorrect — μέθοδος is feminine: Η νέα μέθοδος.
✅ Η νέα μέθοδος δεν δούλεψε καθόλου.
i néa méthodhos dhen dhúlepse kathólu
The new method didn't work at all.
3. Giving a neuter plural noun a feminine or masculine adjective. Neuter plurals take -α, and shoes, shirts and glasses are neuter.
❌ Αγόρασα καινούργιες παπούτσια για τον γάμο.
Incorrect — παπούτσια is neuter plural: καινούργια παπούτσια.
✅ Αγόρασα καινούργια παπούτσια για τον γάμο.
aghórasa kenúrya papútsia ya ton ghámo
I bought new shoes for the wedding.
4. Inflecting only the noun in a genitive phrase. Everything in front of it moves as well.
❌ Το αυτοκίνητο της μεγάλη αδερφής μου χάλασε πάλι.
Incorrect — the adjective is genitive too: της μεγάλης αδερφής μου.
✅ Το αυτοκίνητο της μεγάλης αδερφής μου χάλασε πάλι.
to aftokínito tis meghális adherfís mu chálase páli
My big sister's car has broken down again.
5. Keeping the nominative accent when the phrase goes genitive. Proparoxytone nouns move their accent forward: άνθρωπος → ανθρώπου.
❌ Είναι η γνώμη ενός άνθρωπου, τίποτα παραπάνω.
Incorrect — the genitive shifts the accent: ενός ανθρώπου.
✅ Είναι η γνώμη ενός ανθρώπου, τίποτα παραπάνω.
íne i ghnómi enós anthrópu, típota parapáno
It's one person's opinion, nothing more.
Key Takeaways
- Article, adjectives, determiners and noun all share the same case, gender and number. Decline the phrase as one unit, never word by word.
- Learn the pattern from a worked phrase: ο καλός άνθρωπος → του καλού ανθρώπου → τον καλό άνθρωπο → οι καλοί άνθρωποι → των καλών ανθρώπων → τους καλούς ανθρώπους.
- Agreement is in grammatical value, not in letters: του μεγάλου προβλήματος is a perfectly agreeing genitive with two unrelated endings.
- The adjective follows the noun's gender, not its ending — hence η γνωστή δημοσιογράφος.
- The possessive clitic (μου, σου, του…) is the one element that never changes.
- Concord is what makes Greek word order flexible: a marked object stays an object wherever you move it.
- The vocative takes part too: Αγαπητέ κύριε…, Καλή μου Ελένη.
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Start learning Greek →Related Topics
- Adjective AgreementA1 — The one reflex every Greek adjective demands — copy the noun's gender, number and case onto the adjective, in the attributive slot (ο μεγάλος κήπος → του μεγάλου κήπου) and in the predicative slot after είμαι (το σπίτι είναι μεγάλο) alike — and the two English-speaker errors, leaving the adjective bare and agreeing in gender but not case.
- Article + Adjective + Noun OrderA2 — The frame [article – adjective – noun] and what it means to be inside it: why το άδειο σπίτι and το σπίτι άδειο say different things, how the doubled article of ο άνθρωπος ο καλός works, and why the article alone is what turns καλύτερος into 'the best'.
- Combining DeterminersB2 — English allows one determiner per noun; Greek queues them up — όλα αυτά τα παλιά γράμματα is four words in front of one noun, all four carrying the same gender, number and case. This page gives the ordering template, works one phrase through the nominative, accusative and genitive so you can watch every element shift together, and settles where a numeral, a possessive clitic and 'both' land in the queue.