Masculine Noun Declension in Greek

In Brief

Greek masculine nouns change form according to case (their role in the sentence) and number (singular or plural). For the three main beginner patterns, learn the article and noun together: ο δρόμος → του δρόμου → τον δρόμο, ο πατέρας → του πατέρα, and ο μαθητής → οι μαθητές. The endings are not decoration: they help show who does what to whom.

Overview

A noun is a word used to name a person, place, thing, or idea. Every Greek noun has grammatical gender, and masculine nouns normally appear with masculine forms of the article: ο “the” in the nominative singular, του in the genitive, and τον in the accusative. The article often gives you the clearest early signal of a noun’s case.

A case is a form that marks the noun’s job in a phrase or sentence. Greek has four cases: the nominative usually marks the subject (the person or thing doing the action); the genitive commonly expresses possession or “of”; the accusative usually marks the direct object (the person or thing directly affected by the action) and follows many prepositions; and the vocative is used when speaking directly to someone.

English says “the student,” “of the student,” and “I see the student” without changing the noun. Greek changes both article and ending: ο μαθητής, του μαθητή, βλέπω τον μαθητή. This is a core A1 skill. Begin with the frequent masculine endings -ος, -ας, and -ης, while remembering that not every masculine noun belongs to one of these three groups.

How It Works

First identify case and number

Before choosing an ending, ask two questions:

1. Is the noun singular or plural?
2. What role does it have: subject, possession/relationship, object, or direct address?

The definite article provides a useful framework.

Case	Singular article	Plural article	Typical basic use
Nominative	ο	οι	subject: ο φίλος μιλάει
Genitive	του	των	possession/relationship: το σπίτι του φίλου
Accusative	τον	τους	direct object: βλέπω τον φίλο
Vocative	—	—	direct address: Φίλε!

There is no article in a true vocative phrase. If you call to a person, say Γιώργο! or Κύριε!, not ο Γιώργος!

Pattern 1: nouns ending in -ος

Use δρόμος “road” as a model.

Case	Singular	Plural
Nominative	ο δρόμος	οι δρόμοι
Genitive	του δρόμου	των δρόμων
Accusative	τον δρόμο	τους δρόμους
Vocative	δρόμε	δρόμοι

The practical sequence is:

• singular: -ος, -ου, -ο, -ε
• plural: -οι, -ων, -ους, -οι

The written plural nominative ending -οι and the singular genitive ending -ου are both pronounced /i/ and /u/ respectively according to normal Modern Greek spelling; do not choose them by sound alone when writing. Notice also that nominative οι δρόμοι and vocative δρόμοι have the same noun form, but the vocative has no article.

Stress can move in some words. In δρόμος, it remains on the first syllable in most forms but moves in the genitive plural: δρόμων. Other -ος nouns may follow different stress behavior, so learn the genitive with the noun rather than relying only on the ending.

Pattern 2: nouns ending in -ας

Use πατέρας “father” as a model.

Case	Singular	Plural
Nominative	ο πατέρας	οι πατέρες
Genitive	του πατέρα	των πατέρων
Accusative	τον πατέρα	τους πατέρες
Vocative	πατέρα	πατέρες

The main sequence is:

• singular: -ας, -α, -α, -α
• plural: -ες, -ων, -ες, -ες

For this group, the genitive, accusative, and vocative singular often look identical. The article and sentence context distinguish them: του πατέρα is genitive, τον πατέρα is accusative, and πατέρα! is direct address. In the plural, nominative and accusative nouns also share -ες, while the article changes: οι πατέρες versus τους πατέρες.

The model πατέρας changes its stress and also drops the unstressed vowel found in the nominative: πατέρας → πατέρα → πατέρες → πατέρων. Not every -ας noun behaves identically in stress, so treat the model as a highly useful pattern, not a machine that predicts every detail.

Pattern 3: nouns ending in -ης

Use μαθητής “student” as a model.

Case	Singular	Plural
Nominative	ο μαθητής	οι μαθητές
Genitive	του μαθητή	των μαθητών
Accusative	τον μαθητή	τους μαθητές
Vocative	μαθητή	μαθητές

The main sequence is:

• singular: -ης, -η, -η, -η
• plural: -ες, -ων, -ες, -ες

As with -ας nouns, the article carries a great deal of information. Compare οι μαθητές “the students” with τους μαθητές “the students” as an object. The noun sounds the same, but the article tells you whether it is nominative or accusative.

In this model, stress moves in the genitive plural: μαθητών. This movement is common in many learned and occupational nouns in -της, but stress patterns are lexical—that is, they belong partly to the individual word. Record ο μαθητής, του μαθητή, οι μαθητές, των μαθητών together when learning the noun.

A compact comparison

Form	-ος: δρόμος	-ας: πατέρας	-ης: μαθητής
Nominative singular	ο δρόμος	ο πατέρας	ο μαθητής
Genitive singular	του δρόμου	του πατέρα	του μαθητή
Accusative singular	τον δρόμο	τον πατέρα	τον μαθητή
Vocative singular	δρόμε	πατέρα	μαθητή
Nominative plural	οι δρόμοι	οι πατέρες	οι μαθητές
Genitive plural	των δρόμων	των πατέρων	των μαθητών
Accusative plural	τους δρόμους	τους πατέρες	τους μαθητές
Vocative plural	δρόμοι	πατέρες	μαθητές

For a beginner, the most efficient habit is to learn four anchor forms: nominative singular, genitive singular, nominative plural, and genitive plural. The remaining forms then become much easier to predict.

Examples in Context

Greek	English	Note
Ο δρόμος είναι κλειστός.	The road is closed.	ο δρόμος is the subject.
Δεν ξέρω το όνομα του δρόμου.	I do not know the name of the road.	Singular genitive expresses a relationship: “of the road.”
Περνάμε τον δρόμο.	We are crossing the road.	τον δρόμο is the direct object.
Οι δρόμοι είναι ήσυχοι το βράδυ.	The roads are quiet at night.	Plural nominative in -οι.
Ο χάρτης δείχνει τα ονόματα των δρόμων.	The map shows the names of the roads.	Plural genitive in -ων.
Βλέπω τους φίλους μου κάθε μέρα.	I see my friends every day.	Plural accusative of an -ος noun.
Ο πατέρας μαγειρεύει σήμερα.	The father is cooking today.	Singular nominative in -ας.
Αυτό είναι το αυτοκίνητο του πατέρα μου.	This is my father’s car.	Singular genitive; μου means “my/of me.”
Περιμένω τον πατέρα μου έξω.	I am waiting for my father outside.	Singular accusative after περιμένω.
Πατέρα, πού είσαι;	Dad, where are you?	Vocative, with no article.
Οι πατέρες περιμένουν τα παιδιά.	The fathers are waiting for the children.	Plural nominative in -ες.
Ο μαθητής διαβάζει στην τάξη.	The student is reading in the classroom.	Singular nominative in -ης.
Η τσάντα του μαθητή είναι εδώ.	The student’s bag is here.	Singular genitive in -η.
Η δασκάλα βοηθάει τον μαθητή.	The teacher helps the student.	Singular accusative in -η.
Οι μαθητές μιλούν με τον καθηγητή.	The students are speaking with the teacher.	οι μαθητές is nominative; τον καθηγητή follows με.

These sentences also show an important difference from English. Greek may use word order flexibly for emphasis because the article and ending mark grammatical roles more clearly. At beginner level, a normal subject–verb–object order is safest, but you should still read the case markers rather than guessing from position alone.

Common Mistakes

Keeping the nominative ending everywhere

• Wrong: Βλέπω ο μαθητής.
• Right: Βλέπω τον μαθητή.
• Why: The student is the direct object of “see,” so both article and noun must be accusative.

Changing the article but not the noun

• Wrong: του δρόμος
• Right: του δρόμου
• Why: Agreement here means that article and noun show the same case and number. The genitive singular pair is του δρόμου.

Using singular endings with a plural article

• Wrong: οι δρόμος
• Right: οι δρόμοι
• Why: οι is plural, so the noun must also be plural. For this -ος pattern, nominative plural ends in -οι.

Confusing nominative and accusative plurals

• Wrong: Βλέπω οι μαθητές.
• Right: Βλέπω τους μαθητές.
• Why: The noun form μαθητές is identical in these two cases, but the article is not: οι marks nominative and τους marks accusative.

Adding an article when calling someone

• Wrong: Ο πατέρα, έλα εδώ!
• Right: Πατέρα, έλα εδώ!
• Why: Direct address requires the vocative and normally has no article.

Ignoring stress marks

• Wrong: των μαθητων
• Right: των μαθητών
• Why: Stress is part of Greek spelling and pronunciation. In this genitive plural, it falls on the final syllable.

Usage Notes

The final -ν of τον is part of the standard written masculine accusative article: τον δρόμο, τον πατέρα, τον μαθητή. In rapid speech it may be less prominent, but learners should write and practise the full form. It also helps distinguish masculine τον from feminine τη(ν).

The accusative follows many very common prepositions. Modern Greek prepositions such as με “with,” σε “to/in/at,” για “for,” and από “from” are followed by the accusative: με τον φίλο, για τον μαθητή. When σε combines with the definite article, it contracts: σε + τον = στον, as in στον δρόμο “on/in the road.”

Greek often omits an article where English uses a possessive construction differently, but possession with a noun is regularly expressed through the genitive: το βιβλίο του μαθητή “the student’s book.” Possessive pronouns come after the noun phrase: ο πατέρας μου literally has the structure “the father of me,” meaning “my father.”

Forms of direct address are frequent in everyday conversation. The regular vocative of many -ος common nouns ends in -ε, but personal names and particular noun classes may differ: Γιώργος → Γιώργο, Νίκος → Νίκο. Learn names and common forms of address individually rather than forcing δρόμος’s -ε onto every -ος word.

Beyond the Basics / Advanced Use

You do not need to master every exception at A1, but you will meet more masculine patterns later. Common masculine nouns also end in -ές (ο καφές), -ούς (ο παππούς), -έας (ο συγγραφέας), and other endings. Their plural and genitive forms require separate models; do not automatically decline them like πατέρας or μαθητής merely because the nouns are masculine.

Stress movement deserves special attention. Greek restricts how far stress may stand from the end of a word, and older declensional patterns also influence modern forms. This helps explain contrasts such as ο δρόμος → των δρόμων and ο άνθρωπος → των ανθρώπων. Yet analogy and everyday usage produce variation across words, so the safest vocabulary entry includes an article and key forms, not just a bare nominative.

Some nouns have alternative forms depending on register. Formal, technical, or learned vocabulary may preserve less predictable genitives or plurals, while conversation may prefer a more regular form or avoid a rare genitive. Dictionaries normally list the gender and enough forms to reveal the pattern. At higher levels, check a reliable dictionary when writing formal Greek instead of guessing.

Finally, case is not determined only by meaning. A verb or preposition may require a particular construction, and the genitive has uses beyond simple possession. Those broader choices belong to advanced case study. For now, secure the core contrast: nominative subject, genitive relationship or possession, accusative object or prepositional complement, and vocative direct address.

Practice Tips

1. Learn nouns as four-part bundles. Instead of memorising only δρόμος, say aloud: ο δρόμος, του δρόμου, οι δρόμοι, των δρόμων. Do the same with one -ας and one -ης noun.
2. Transform one short sentence. Start with Ο μαθητής βλέπει τον καθηγητή. Swap the people, make them plural, or add possession. Each change forces you to choose the article and ending consciously.
3. Color-code the article and ending. In your notes, underline του...-ου, τον...-ο, and των...-ων. This trains you to see each noun phrase as a unit rather than treating the article and noun separately.

Related Concepts

• Prerequisite: Case System Introduction — introduces the four Greek cases and their basic sentence roles.