Spelling the /i/ Sound: η ι υ ει οι

If there is one page in the whole Greek spelling section to study hard, it is this one. The sound /i/ — the "ee" in "see" — can be written five different ways: η, ι, υ, ει, and οι (and, in a handful of learned words, a sixth, υι). All six are pronounced exactly the same. There is no audible clue whatsoever telling you which spelling a given word takes; you cannot sound it out. This is the number-one spelling challenge for learners and for native Greeks, and it is drilled for years in Greek schools. The path through it is not memorising every word — it's learning the grammatical patterns and word families that make most of the choices for you.

Five (or six) letters, one sound

Here are all the spellings of /i/, each in a real word:

That one sentence uses three of the /i/-spellings: η (the article — twice — and again in μεγάλη and αδερφή), ι and η together in Νίκη, and ει in είναι. Read aloud, every /i/ is the same sound; on the page, three different letters.

The high-value patterns

Most of your /i/ letters sit in endings, and endings are predictable. Learn these five patterns and you'll spell the majority of /i/ sounds correctly without knowing anything about the individual word.

Pattern 1 — Feminine nouns end in -η

A very large class of feminine nouns ends in -η: νίκη, τιμή, αγάπη, τέχνη, ζωή, φωνή. If a noun is feminine and ends in the /i/ sound (and isn't from the -ις / -η type of loanword), reach for η first.

Note that δυνατή ("strong," feminine) also ends in -η — because adjective feminines follow the same rule (Pattern 4 below). More on why the ending signals gender on the noun gender page.

Pattern 2 — Neuter nouns (especially diminutives) end in -ι

A big family of neuter nouns ends in -ι (iota): παιδί, σπίτι, κλειδί, τραπέζι, ποτήρι, ψωμί. (Other neuters end in -ο or -ό — δώρο, νερό — but when the ending sounds like /i/, it's spelled -ι.) Above all, diminutives in -άκι always take iota: καφεδάκι, σπιτάκι, παιδάκι, κοριτσάκι.

Pattern 3 — Verb endings: -εις (2sg) and -ει (3sg)

The present-tense endings for "you" (singular) and "he/she/it" are spelled with ει: γράφεις, γράφει; τρέχεις, τρέχει; θέλεις, θέλει. These never take η or ι — the ending is fixed.

This one is pure gold, because these are among the most frequent word-endings in the language, and they're always -εις / -ει.

Pattern 4 — Adjective feminine singular ends in -η

Just like feminine nouns, the feminine form of most adjectives ends in -η: καλή, μικρή, μεγάλη, όμορφη, ωραία? no (that's -α), but ακριβή, φτηνή, δυνατή. Where the masculine ends in -ος and the feminine sounds like /i/, it's spelled -η.

Notice πόλη ("town") also ends in -η — it's one of the feminine -η nouns from Pattern 1.

Pattern 5 — Learned and scientific words keep υ

Words inherited more directly from Ancient Greek — and the international scientific vocabulary built from Greek roots — tend to keep the etymological υ: σύστημα, γύρος, μυστικό, γυμναστήριο, φύση, ύλη, σύμβολο, τύπος. If a word feels "learned," formal, or technical, υ is a good bet.

And οι — the masculine plural ending

The spelling οι shows up above all as the nominative plural of masculine nouns and their article: ο άνθρωπος → οι άνθρωποι, ο δρόμος → οι δρόμοι, ο φίλος → οι φίλοι. Whenever you make a masculine noun plural in the subject position, both the article οι and the ending -οι take omicron-iota.

Word families keep their spelling

Beyond the endings, remember that a root carries its spelling into every relative. Learn that γράφω has ει nowhere but its family shares γρα-; learn that κρύ- ("cold/hidden") has υ, and κρύο, κρυώνω, κρύβω, κρυφός all keep it. Recognising the family means you spell a dozen words from knowing one.

Homophones told apart only by their /i/-spelling

Because five letters share one sound, Greek is full of word pairs that sound identical and are distinguished purely by which /i/-letter they use. The spelling is the meaning:

Say it aloud and καλή and καλεί are the same syllables; only the page tells them apart. This is why Greek treats spelling as real content, not a formality — and why the endings (Pattern 3 explains καλεί's -εί; Pattern 4 explains καλή's -ή) are your fastest way to get homophones right.

Common Mistakes

1. Ending a feminine noun in -ι instead of -η. The default feminine ending is -η.

2. Writing a verb's 3sg ending as -η. The present 3rd-person singular ending is always -ει.

3. Replacing a learned υ with ι. Words from the learned/scientific stock keep the etymological υ.

4. Confusing a homophone pair. κλείνω ("I close") and κλίνω ("I bend/decline") sound the same; the spelling picks the meaning.

5. Spelling a masculine plural with η or ι. The subject-plural ending (and its article) is -οι / οι.

Key Takeaways

• η, ι, υ, ει, οι (and rare υι) all sound identical: /i/. You can't hear which a word takes.
• Attack it through endings: feminine noun/adjective -η (νίκη, καλή), neuter and diminutive -ι / -άκι (παιδί, καφεδάκι), verb -εις / -ει (γράφεις, γράφει), masculine plural -οι (οι δρόμοι).
• Learned and scientific words keep υ (σύστημα, γύρος), and word families share a root spelling (κρύο, κρυώνω, κρύβω).
• The letters carry meaning in homophones: καλή vs καλεί, κλείνω vs κλίνω, λύπη vs λείπει.
• See the spelling overview for the why, vowel digraphs for how ει and οι are read, and noun gender for why -η signals a feminine.