Abstract nouns let Greek name a quality or state as a thing: ίσος → ισότητα “equal → equality,” δίκαιος → δικαιοσύνη “just → justice,” ελεύθερος → ελευθερία “free → freedom.” The families are useful for decoding, but suffix choice, stem shape, stress, spelling, and exact meaning belong to each accepted lexeme.
The main quality-noun families
| Adjective or base | Abstract noun | Core meaning | Pattern |
|---|---|---|---|
| ίσος | η ισότητα | equality | -ότητα |
| απλός | η απλότητα | simplicity | -ότητα |
| πιθανός | η πιθανότητα | probability, possibility | -ότητα |
| ταχύς | η ταχύτητα | speed | -ύτητα |
| δίκαιος | η δικαιοσύνη | justice | -οσύνη |
| καλός | η καλοσύνη | kindness, goodness | -οσύνη |
| ευτυχής | η ευτυχία | happiness | -ία |
| ελεύθερος | η ελευθερία | freedom | -ία |
| ακριβής | η ακρίβεια | accuracy; expensiveness | -εια |
| ευγενής | η ευγένεια | politeness, nobility | -εια |
All these nouns are feminine, but they do not all share one ending or one declension.
-ότητα and its -ύτητα allomorph
-ότητα commonly attaches to adjectival stems and names the corresponding quality: ίσος → ισότητα, απλός → απλότητα, πιθανός → πιθανότητα. With many learned adjectives in -ύς, the related shape is -ύτητα: ταχύς → ταχύτητα, βαρύς → βαρύτητα. This is an allomorphic family, not a free choice between two suffixes.
Η ισότητα απέναντι στον νόμο αποτελεί βασική αρχή.
i isótita apénandi ston nómo apotelí vasikí archí.
Equality before the law is a fundamental principle. (formal)
Η ταχύτητα του ανέμου αυξήθηκε μέσα σε λίγα λεπτά.
i tachítita tu anému afksíthike mésa se lígha leptá.
The wind speed increased within a few minutes.
Υπάρχει μεγάλη πιθανότητα να βρέξει το απόγευμα.
ipárchi megháli pithanótita na vréksi to apóyevma.
There is a strong possibility that it will rain this afternoon.
Stress often differs from the adjective: ίσος → ισότητα, ταχύς → ταχύτητα. Learn the pair aloud rather than assuming the adjective's accent stays in place.
-οσύνη: qualities with a human or evaluative flavor
-οσύνη frequently names a character quality, disposition, collective identity, or valued condition. High-frequency examples include δικαιοσύνη, καλοσύνη, εμπιστοσύνη. The base can change shape: δίκαιος contributes δικαιο-, and έμπιστος corresponds to εμπιστοσύνη.
Χωρίς δικαιοσύνη δεν μπορεί να υπάρξει πραγματική ειρήνη.
chorís dhikeosíni dhen borí na ipárksi praghmatikí iríni.
Without justice, there can be no real peace.
Δεν θα ξεχάσω την καλοσύνη που μας έδειξαν εκείνο το βράδυ.
dhen tha ksecháso tin kalosíni pu mas édhiksan ekíno to vrádhi.
I will not forget the kindness they showed us that evening.
Η εμπιστοσύνη χτίζεται αργά και χάνεται εύκολα.
i ebistosíni chtízete arghá ke chánete éfkola.
Trust is built slowly and lost easily.
These nouns end in -η: της καλοσύνης, της δικαιοσύνης. Their basic declension follows the regular feminine -η pattern described on feminine nouns in -η. Many abstract senses are normally singular; a plural appears only when the meaning supports separate instances or kinds.
-ία and -εία: a lexical spelling contrast
-ία appears in ευτυχία, ελευθερία, δυσκολία. The spelling -εία appears in words such as ακρίβεια and ευγένεια. Modern pronunciation does not give English-speaking learners a reliable way to choose the written sequence: the spelling must be learned with the word.
Η ελευθερία της έκφρασης συνοδεύεται από ευθύνη.
i elefthería tis ékfrasis sinodhévete apó efthíni.
Freedom of expression comes with responsibility. (formal)
Η ευτυχία της φαινόταν στο πρόσωπό της.
i eftichía tis fenótan sto prósopó tis.
Her happiness showed on her face.
Η ακρίβεια των μετρήσεων επηρεάζει το τελικό αποτέλεσμα.
i akrívia ton metríseon epireázi to telikó apotélezma.
The accuracy of the measurements affects the final result. (technical)
Η ευγένεια δεν κοστίζει τίποτα και αλλάζει το κλίμα.
i evyénia dhen kostízi típota ke alázi to klíma.
Politeness costs nothing and changes the atmosphere.
English -ness, -ity, and -dom do not map consistently onto one Greek suffix. “Freedom” uses -ία, “kindness” uses -οσύνη, and “equality” uses -ότητα.
Feminine declension and number
Nouns in -ότητα / -ύτητα and -ία / -εία decline as feminines in -α: της ισότητας, οι πιθανότητες, της ελευθερίας. Nouns in -οσύνη decline as feminines in -η: της δικαιοσύνης, οι καλοσύνες. Plurals are possible, but genuinely abstract meanings often prefer the singular.
Εξετάσαμε όλες τις πιθανότητες πριν πάρουμε απόφαση.
eksetásame óles tis pithanótites prin párume apófasi.
We considered every possibility before making a decision.
Η προστασία των ατομικών ελευθεριών είναι ευθύνη της πολιτείας.
i prostasía ton atomikón eleftherión íne efthíni tis politías.
Protecting individual freedoms is the responsibility of the state. (formal)
The lexical caveat: δουλειά
Δουλειά “work, job” belongs to the same broad family as δουλεύω “work,” but current learners should treat it as a lexical word, not as proof that attaching -ία to a verb freely creates a noun. Its stem, stress, synizesis -ιά, and range of meanings are learned as a whole.
Βρήκε δουλειά κοντά στο σπίτι και γλίτωσε τη μεγάλη διαδρομή.
vríke dhuliá kondá sto spíti ke ghlítose ti megháli dhiadhromí.
She found a job near home and avoided the long commute.
Action nouns made from verbs are treated separately on nouns from verbs.
Common Mistakes
Treating every adjective as if it selected -ότητα
The accepted noun may use another suffix or a changed stem.
Από το επίθετο «καλός» μαθαίνουμε το ουσιαστικό «καλοσύνη» ως ολόκληρο ζευγάρι.
apó to epítheto «kalós» mathénume to usiastikó «kalosíni» os olókliro zevghári.
From the adjective καλός, we learn the noun καλοσύνη as part of a complete pair.
Assigning neuter gender to an abstract idea
These families are feminine regardless of the English translation.
Η απλότητα της λύσης εντυπωσίασε την ομάδα.
i aplótita tis lísis endiposíase tin omádha.
The simplicity of the solution impressed the team.
Keeping the adjective's stress automatically
Derivation may move stress or expose a different stem.
Οι λέξεις ίσος και ισότητα δεν τονίζονται στην ίδια συλλαβή.
i léksis ísos ke isótita dhen tonízonde stin ídhia silaví.
The words ίσος and ισότητα are not stressed on the same syllable.
Guessing -ία versus -εία from sound
Modern pronunciation does not reliably reveal the spelling.
Σημείωσα χωριστά την ορθογραφία των λέξεων ευτυχία και ακρίβεια.
simíosa choristá tin orthoghrafía ton lékseon eftichía ke akrívia.
I noted the spelling of ευτυχία and ακρίβεια separately.
Key Takeaways
- -ότητα / -ύτητα often names an adjectival quality; the allomorph follows the established stem.
- -οσύνη frequently names human, evaluative, or collective qualities.
- -ία / -εία is a lexical spelling contrast that sound alone does not settle.
- These nouns are feminine, but -α and -η endings follow different declensional details.
- Derivational families aid recognition; they do not license a mechanical noun from every adjective or verb.
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