In short

Feminine nouns are the easiest gender to decline, because in the singular almost nothing moves. The vast majority end in -α (η ώρα) or -η (η αγάπη), and inside the singular only the genitive changes: it adds a final -ς — της ώρας, της αγάπης. Nominative, accusative and vocative are all identical.

The plural is where you have to choose. Most -α and -η nouns make -ες in the plural (οι ώρες, οι αγάπες) with the genitive plural stressed on the very last syllable (των ωρών, των νικών). But abstracts in -ση, -ξη, -ψη — plus η πόλη — make -εις instead: οι πόλεις, των πόλεων, τις πόλεις.

Two smaller groups complete the picture: nouns in -ος that look masculine but are feminine (η οδός, η μέθοδος), and a small everyday group — η γιαγιά / η αλεπού — which builds its plural with -δες.

The rule

1. The article does the heavy lifting. The feminine article is η / της / τη(ν) in the singular and οι / των / τις in the plural. Even when two forms of the noun look the same, the article tells you the case: η ώρα (nominative) against την ώρα (accusative).

2. The genitive singular -ς. This is the single most useful ending in the lesson. Add -ς to the nominative and you have the genitive: η γυναίκα → της γυναίκας, η πόλη → της πόλης, η γιαγιά → της γιαγιάς. Leaving it off (*της γυναίκα) is the classic beginner error.

3. The genitive plural pulls the accent to the end. For most -α and -η nouns the genitive plural ending -ών is stressed, wherever the accent sat before: η γυναίκα → των γυναικών, η θάλασσα → των θαλασσών, η νίκη → των νικών. Three sets of exceptions: a large group of nouns keeps an unstressed -ων instead (η μητέρα → των μητέρων, η εικόνα → των εικόνων); the whole -ση/-ξη/-ψη group keeps the accent where the plural has it — των κυβερνήσεων, των πόλεων; and a further group has no genitive plural in use at all, so there is nothing to build — η αγάπη is one of them (*των αγαπών is not a Greek form).

4. -ση, -ξη, -ψη (and πόλη) pluralise in -εις. These are abstract or institutional nouns: η κυβέρνηση, η λέξη, η σκέψη, η τάξη, η άσκηση. Their plural nominative and accusative are identical (οι πόλεις / τις πόλεις) — again, the article disambiguates.

5. Feminines in -ος decline like masculine -ος nouns in every case but the vocative, and every article around them is feminine: η οδός, της οδού, την οδό, οι οδοί, των οδών, τις οδούς. The group is small but frequent in signs, addresses and academic prose: η οδός, η είσοδος, η έξοδος, η μέθοδος, η περίοδος, η διάμετρος, η ήπειρος. If a proparoxytone noun of this type is put in the genitive singular, the genitive plural or the accusative plural, the accent moves one syllable towards the end: η είσοδος → της εισόδου, των εισόδων, τις εισόδους.

6. The -δες type. Feminines in a stressed -ού — η αλεπού, η μαϊμού — keep that stress everywhere and all take -δες in the plural: αλεπούδες, μαϊμούδες. Note their genitive singular: της αλεπούς. A stressed -ά does not do this by itself: only a handful of familiar words (η γιαγιά, η προγιαγιά, η μαμά, η νταντά) join the -δες type — γιαγιάδες, μαμάδες — while the ordinary nouns in stressed -ά make plain -ές: η καρδιά → οι καρδιές, η φωτιά → οι φωτιές, η αγορά → οι αγορές.

7. Final -ν on the article. Write την before a vowel and before κ, π, τ, γκ, μπ, ντ, τσ, τζ, ξ, ψ; write τη elsewhere: την ώρα, την πόλη, την κυβέρνηση — but τη γυναίκα, τη θάλασσα, τη λέξη.

Forms & patterns

Type 1 — nouns in -α (plural -ες). η ώρα is stressed on the penult, η γυναίκα too, η θάλασσα on the antepenult; all three behave alike.

Type 2 — nouns in -η (plural -ες). Identical endings, with -η where type 1 has -α. One cell is genuinely empty: αγάπη belongs to the sub-group with no genitive plural in use, while νίκη shows the regular form.

Type 3 — the -ση / -ξη / -ψη abstracts, plus η πόλη (plural -εις). The singular is exactly like type 2; only the plural differs. Watch the accent in κυβέρνηση: the plural moves it one syllable towards the end — κυβερνήσεις, των κυβερνήσεων.

Type 4 — feminines in -ος. The endings are the masculine ones everywhere except the vocative; the articles are feminine. Note the accent shift in της εισόδου, της μεθόδου, των εισόδων, των μεθόδων, τις εισόδους, τις μεθόδους.

These are things, not people, so the vocative is theoretical — the brackets mark it as a form you construct rather than hear. When it is needed it simply copies the accusative; it does not take the masculine -ε (not *οδέ, not *μέθοδε). You will never call out to a street anyway.

Type 5 — the -δες nouns: every -ού feminine, plus a few familiar words in -ά. The accent never moves.

The same pattern gives η μαμά – οι μαμάδες and η μαϊμού – οι μαϊμούδες. Do not extend it to ordinary nouns in -ή such as η αλλαγή or η ζωή, and above all not to the much larger family of nouns in stressed -ά — η καρδιά, η φωτιά, η αγκαλιά, η αγορά. All of those take type 2 endings: οι αλλαγές, οι ζωές, οι καρδιές, οι φωτιές, οι αγορές.

Examples

Common mistakes

• της γυναίκα -> της γυναίκας — the genitive singular of every feminine noun adds a final -ς; it is the only singular ending that changes.
• της πόλη -> της πόλης — same rule for the -η type; the article alone is not enough.
• οι πόλες -> οι πόλεις — πόλη and the -ση/-ξη/-ψη abstracts take -εις, not -ες.
• οι κυβερνήσες -> οι κυβερνήσεις — and mind the accent: κυβέρνηση but κυβερνήσεις.
• των θάλασσων -> των θαλασσών — the -α and -η type normally makes its genitive plural in -ών, with the stress on the ending.
• των πόλεών -> των πόλεων — the -εις group does the opposite and keeps its accent where the plural puts it.
• ο οδός, τον οδό -> η οδός, την οδό — οδός is feminine; the -ος ending is masculine only in shape, so all its articles and adjectives are feminine (η κεντρική οδός).
• της μέθοδου -> της μεθόδου — proparoxytone -ος feminines shift the accent forward in the genitive, exactly like ο άνθρωπος → του ανθρώπου.
• της αλεπού -> της αλεπούς — the -ού nouns take -ς in the genitive singular too.
• οι μαμές -> οι μαμάδες — γιαγιά, μαμά, αλεπού and μαϊμού build their plural with -δες and with nothing else; there is no *οι γιαγιές beside οι γιαγιάδες.
• οι καρδιάδες -> οι καρδιές — the -δες group is a closed handful of words. Every other noun in stressed -ά (καρδιά, φωτιά, αγορά) takes the type 2 ending -ές.

Tips

• Learn every new feminine noun as a pair: nominative + plural (η ώρα – οι ώρες, η πόλη – οι πόλεις, η γιαγιά – οι γιαγιάδες). The singular then costs you nothing, since only the -ς of the genitive is left to add.
• A quick spelling test for the -εις group: if the noun names an action or an abstract thing and ends in -ση, -ξη or -ψη (η σκέψη, η τάξη, η άσκηση, η απόφαση), its plural is -εις. η πόλη joins the group even though it has no σ.
• Say the genitive plural out loud with the stress hammered onto the end: των ωρών, των γυναικών, των θαλασσών, των νικών. In everyday speech Greeks often avoid this form altogether and rephrase with από or με — but you still need to recognise it in writing.
• Choose between τη and την by ear on the following word: την before a vowel and before κ, π, τ, γκ, μπ, ντ, τσ, τζ, ξ, ψ, τη everywhere else.
• When a feminine noun stressed on its third-from-last syllable takes a weak possessive pronoun, write the second accent: η θάλασσά μας, η κυβέρνησή μας, η μέθοδός του. Nouns like γιαγιά or ώρα never need it.
• Signs and addresses give you the -ος feminines for free: η οδός, η είσοδος, η έξοδος, η περίοδος, η μέθοδος, η διάμετρος. Collect them as a closed list, because nothing in their shape warns you that they are feminine.
• If you are unsure of a feminine noun’s gender, remember that the ending -ος never decides it. Only the article does: του δρόμου is masculine, της οδού is feminine.