Ancient Greek/Basic Nouns/Second Declension

The second declension, in contrast to the first, consists primarily of masculine and neuter nouns. It is occasionally referred to as the ο-declension, because of the recurrence of the vowel omicron. It is the simplest of the three declensions of Ancient Greek, featuring a bit more than a single set of endings, and regular persistent accentuation throughout.

As in the first declension, the declension remains identical in the nominative, vocative, and accusative of the dual. Moreover, after one recognizes the basic second declension (which in many ways is similar to the first declension), the accentuation is similar to that of the first declension: ἄνθρωπος like ὕγίεɩᾰ; θεός and πτερόν like θεᾱ́ or ἡδονή.

Masculine and feminine nouns

These can be recognized by their -ος ending, which was transliterated as -us in Latin and found its way into English (e.g., "Dionysus"). The vast majority of these are masculine.

ἄνθρωπος, ἀνθρώπου, (ánthrōpos, anthrópou) m, "man; human being"

	Singular	Dual	Plural
Nominative	ἄνθρωπος	ἀνθρώπω	ἄνθρωποι
Genitive	ἀνθρώπου	ἀνθρώποιν	ἀνθρώπων
Dative	ἀνθρώπῳ	ἀνθρώποιν	ἀνθρώποις
Accusative	ἄνθρωπον	ἀνθρώπω	ἀνθρώπους
Vocative	ἄνθρωπε	ἀνθρώπω	ἄνθρωποι

The nominative and vocative plurals are always identical. Note that the lengthening of the ending causes the accent to shift (as the accent cannot stand on the antepenult if the ultima is long) in several of the cases. Also recall that final -οι is usually short.

θεός, θεοῦ, (theós, theoû) m, "god"

	Singular	Dual	Plural
Nominative	θεός	θεώ	θεοί
Genitive	θεοῦ	θεοῖν	θεῶν
Dative	θεῷ	θεοῖν	θεοῖς
Accusative	θεόν	θεώ	θεούς
Vocative	θεέ	θεώ	θεοί

νῆσος, νήσου, (nêsos, nésou) f, "island"

	Singular	Dual	Plural
Nominative	νῆσος	νήσω	νῆσοι
Genitive	νήσου	νήσοιν	νήσων
Dative	νήσῳ	νήσοιν	νήσοις
Accusative	νῆσον	νήσω	νήσους
Vocative	νῆσε	νήσω	νῆσοι

Again, note the persistent accent, which changes to an acute before long endings, as expected.

Neuter nouns

These end in -ον and have the nominative, accusative, and vocative identical in both the singular and the plural, which is a feature of all neuter nouns in Ancient Greek:

πτερόν, πτεροῦ, (pterón, pteroû) n, "wing"

	Singular	Dual	Plural
Nominative	πτερόν	πτερώ	πτερά
Genitive	πτεροῦ	πτεροῖν	πτερῶν
Dative	πτερῷ	πτεροῖν	πτεροῖς
Accusative	πτερόν	πτερώ	πτερά
Vocative	πτερόν	πτερώ	πτερά

Note that, except in the nominative, accusative, and vocative, the endings are identical to those of masculine and feminine nouns of the second declension. Also note that, just as in the first declension, whenever a noun of the second declension is accented on the ultima, the accent changes to a circumflex in the genitive and dative singular and plural.