Ancient Greek nouns

In Ancient Greek, all nouns are classified according to grammatical gender (masculine, feminine, or neuter) and are used in a number (singular, dual, or plural). According to their function in a sentence, their form changes to one of the five cases (nominative, vocative, accusative, genitive, or dative). The set of forms that a noun will take for each case and number is determined by the declension that it follows.

Cases

The five cases of Ancient Greek each have different functions.

Nominative

The Ancient Greek nominative, like the Proto-Indo-European nominative, is used for the subject and for things equal to the subject (predicate nouns or adjectives):

• ὁ Σωκράτης ἦν σοφός.

ho Sōcrátēs ên sophós.

"Socrates was wise."

Vocative

The vocative is used for addressing people or things. It is frequently the same as the nominative in the singular and always the same in the plural.

• ὦ Ἀλέξανδρε , Ἰᾶσον, ἔλθετε.

ô Aléksandre, Iâson, élthete

"Alexander, Jason, come."

Accusative

The accusative has meanings derived from the Proto-Indo-European accusative:

• ἔφαγε τὸ βρῶμα.

éphage tò brôma

"He ate the food."

When it is used with prepositions, it frequently indicates motion towards.

Genitive

The Ancient Greek genitive corresponds to the Proto-Indo-European genitive or ablative. When the genitive corresponds to the PIE genitive, it has meanings that can often be translated with the preposition "of" or the English possessive case:

• ὁ Ἀλέξανδρος εἰσῆλθε εἰς τὴν τοῦ Παρμενίωνος οἰκίαν.

ho Aléksandros eisêlthe eis tèn toû Parmeníōnos oikían

"Alexander entered the house of Parmenion." (or "Parmenion's house")

When the genitive corresponds to the Proto-Indo-European ablative case (this is the case when it is used with prepositions), it can often be translated by "from":

• τοῦ Ὁμήρου ἔμαθον τὴν τῶν ἐπῶν ποίησιν.

toû Homérou émathon tèn tôn epôn poíēsin

"From Homer I learned the composition of epic poetry."

Dative

The Ancient Greek dative corresponds to the Proto-Indo-European dative, instrumental, or locative. When it corresponds to the dative, it expresses the person or thing that is indirectly affected by an action, and can often be translated with the prepositions "to" or "for":

• ὁ Ἰησοῦς εἶπε τῷ Παύλῳ: ἐλθὲ μετ' ἐμοῦ.

ho Iēsoûs eîpe tōî Paúlōi: elthè met' emoû.

"Jesus said to Paul: Come with me."

When the dative corresponds to the Proto-Indo-European instrumental, it expresses the thing with which something is done, and can often be translated by the preposition "with" or (rarely) the suffix "-wise":

• κόπτω πελέκει.

kóptō pelékei.

"I am cutting with an axe."

When the dative corresponds to the Proto-Indo-European locative case (this is often the case when it is used with prepositions), it expresses location (sometimes figuratively) or time, and can often be translated by "in", "at", or "on"::

• ἑβδομηκοστῷ ἔτει ὁ Σωκράτης ἀπέθανε.

hebdomēkostōî étei ho Sōkrátēs apéthane.

"In his seventieth year Socrates died."

Declension

Accent of strong and weak cases

For first- and second-declension nouns accented on the ultima and third-declension nouns with a single-syllable stem, the strong cases (nominative and accusative) have one type of accent, and the weak cases (genitive and dative) have another.

Specifically, the first- and second-declension nouns have acute in the strong cases, but circumflex in the weak cases:

• ἀγορά, ἀγοράν—ἀγορᾶς, ἀγορᾷ "gathering, marketplace"
• ἀγοραί, ἀγοράς—ἀγορῶν, ἀγοραῖς
• θεός, θεόν—θεοῦ, θεῷ "god"
• θεοί, θεούς—θεῶν, θεοῖς

Third-declension nouns accent the stem in the strong cases, but the ending in the weak cases:

• πούς, πόδα—ποδός, ποδί "foot"
• πόδες, πόδας—ποδῶν, ποσί

Both of these patterns are summarized by a single rule: pre-ending accent in the strong cases and post-stem accent in the weak cases.^[1]

For first- and second-declension nouns, the rule is more complex. The thematic vowel (ο or ᾱ) counts as neither stem nor ending, but alternates between the two depending on which accent is considered. For post-stem accent, it counts as part of the ending; for pre-ending accent, it counts as part of the stem.

	pre-ending accent		post-stem accent
1st decl.	ἀγοραά-	ἀγοραά-ν	ἀγορ-άὰς	ἀγορ-άαεὶ
	ἀγορά-ι̯	ἀγοραά-νς	ἀγορ-άαὼν	ἀγορ-άαὶς
2nd decl.	θεό-ς	θεό-ν	θε-όὸ	θε-όεὶ
	θεό-ι̯	θεό-νς	θε-όὼν	θε-όὶς
3rd decl.	πόδ-ς	πόδ-ν	ποδ-ός	ποδ-ί
	πόδ-ες	πόδ-νς	ποδ-όον	ποδ-σί

First declension

The first declension or alpha declension is considered thematic, with long alpha (ᾱ) at the end of the stem, though it is derived from original athematic Indo-European forms. In Attic Greek, this changes to η everywhere except after ε, ι or ρ. The first declension includes mostly feminine nouns, but also a few masculine nouns, including agent nouns in -της, patronyms in -ίδης, and demonyms.

The first-declension genitive plural always takes a circumflex on the last syllable. In Homeric Greek the ending was -άων (ᾱ) or -έων (from quantitative metathesis of *-ηων). -έων was contracted to -ῶν in Attic.^[2]

Feminine long a-stem

	feminine: ἡ
	ᾱ						η
	χώρᾱ- "country"		θεᾱ´- "goddess"		οἰκίᾱ- "house"		φωνή- "voice"
	sg.	pl.	sg.	pl.	sg.	pl.	sg.	pl.
nominative	χώρᾱ	χῶραι	θεά	θεαί	οἰκίᾱ	οἰκίαι	φωνή	φωναί
vocative
accusative	χώρᾱν	χώρᾱς	θεάν	θεάς	οἰκίᾱν	οἰκίᾱς	φωνήν	φωνάς
genitive	χώρᾱς	χωρῶν	θεᾶς	θεῶν	οἰκίᾱς	οἰκιῶν	φωνῆς	φωνῶν
dative	χώρᾳ	χώραις	θεᾷ	θεαῖς	οἰκίᾳ	οἰκίαις	φωνῇ	φωναῖς

Feminine short a-stem

Some nouns have short ᾰ in the nominative, accusative, and vocative singular,^[3] but are otherwise identical to other feminine first-declension nouns. They are recessively accented.

These were formed with the suffix -ι̯ᾰ or ιᾰ.^[4] The ι̯ (written as *y or *i̯ in Proto-Indo-European notation, representing the semivowel [j]) undergoes one of several sound changes with the consonant at the end of the stem:

• *γλωχ-ι̯ᾰ → γλῶσσᾰ, Attic γλῶττᾰ "tongue" (palatalization;^[5] compare γλωχῑν "point")
• *μορ-ι̯ᾰ → μοῖρᾰ "portion" (metathesis;^[6] compare μόρος)
• *γεφυρ-ι̯ᾰ → γέφῡρᾰ "bridge" (compensatory lengthening of υ after loss of ι̯)^[7]
• *ἀληθεσ-ι̯ᾰ → ἀλήθειᾰ "truth" (assimilation of σ to ι̯; compare ἀληθές "something true")

	feminine: ἡ
	ᾱ		η
	ἀληθείᾱ- (ᾰ-) "truth"		γλώσση- (ᾰ-) "tongue"
	sg.	pl.	sg.	pl.
nominative	ἀλήθειᾰ	ἀλήθειαι	γλῶσσᾰ	γλῶσσαι
vocative
accusative	ἀλήθειᾰν	ἀληθείᾱς	γλῶσσᾰν	γλώσσᾱς
genitive	ἀληθείᾱς	ἀληθειῶν	γλώσσης	γλωσσῶν
dative	ἀληθείᾳ	ἀληθείαις	γλώσσῃ	γλώσσαις

Masculine a-stem

Masculine first-declension nouns end in -ᾱς or -ης in Attic. Homer retains the older masculine ending -ᾱ and uses ναύτᾱ "sailor" instead of ναύτης: compare Latin nauta.

The masculine genitive singular ending comes from the second declension.^[8] Homeric Greek uses -ᾱο or -εω.^[2]

	masculine: ὁ
	ᾱς		ης
	νεᾱνίᾱ- "young man"		ποιητή- "creative artist"
	sg.	pl.	sg.	pl.
nominative	νεᾱνίᾱς	νεᾱνίαι	ποιητής	ποιηταί
vocative	νεᾱνίᾱ		ποιητά (ᾰ)
accusative	νεᾱνίᾱν	νεᾱνίᾱς	ποιητήν	ποιητάς
genitive	νεᾱνίου	νεᾱνιῶν	ποιητοῦ	ποιητῶν
dative	νεᾱνίᾳ	νεᾱνίαις	ποιητῇ	ποιηταῖς

Second declension

The second or omicron declension is thematic, with an -ο or -ε at the end of the stem. It includes one class of masculine and feminine nouns and one class of neuter nouns.

When a second-declension noun is accented on the ultima, the accent switches between acute for the nominative, accusative, and vocative, and circumflex for the genitive and dative. The only exceptions are Attic-declension and contracted nouns.

Masculine and feminine o-stems

Masculine and feminine both end in -ος, and can only be distinguished by an article or adjective.

	masculine: ὁ		feminine: ἡ
	ἄνθρωπο- "person"		ὁδό- "way"
	sg.	pl.	sg.	pl.
nominative	ἄνθρωπος	ἄνθρωποι	ὁδός	ὁδοί
vocative	ἄνθρωπε		ὁδέ
accusative	ἄνθρωπον	ἀνθρώπους	ὁδόν	ὁδούς
genitive	ἀνθρώπου	ἀνθρώπων	ὁδοῦ	ὁδῶν
dative	ἀνθρώπῳ	ἀνθρώποις	ὁδῷ	ὁδοῖς

Neuter o-stems

In the neuter, the nominative, accusative, and vocative are the same, with a singular in -ον and plural in -ᾰ. Other forms are identical to the masculine and feminine second declension.

	neuter: τό
	δῶρο- "gift"
	singular	plural
nominative	δῶρον	δῶρᾰ
vocative
accusative
genitive	δώρου	δώρων
dative	δώρῳ	δώροις

Attic declension

In the Attic dialect, some second-declension nouns and adjectives have endings with lengthened vowels. When a noun or adjective ends in -ηος or -ηον, quantitative metathesis (switching of vowel lengths) changes it to -εως or -εων.

• ο, ου, α → ω
• οι → ῳ
• original ῳ remains.

The placement of the accent does not change, even when the ultima is long, and all forms take an acute instead of a circumflex.

In these nouns, the vocative singular is the same as the nominative singular.

masculine λεω- "people" sg. pl. nominative λεώς λεῴ vocative accusative λεών λεώς genitive λεώ λεών dative λεῴ λεῴς

neuter ἔμπλεω- "quite full" sg. pl. nominative ἔμπλεων ἔμπλεω vocative accusative genitive ἔμπλεω ἔμπλεων dative ἔμπλεῳ ἔμπλεῳς

Contracted second declension

In Attic, nouns and adjectives ending in -εος or -οος and -εον or -οον are contracted so that they end in -ους and -ουν.

When the ultima is accented, it takes a circumflex in all forms, including the nominative, accusative, and vocative.

	masculine
	νοῦ- (νόο-) "mind"
	sg.	pl.
nominative	νοῦς	νοῖ
vocative	νοῦ
accusative	νοῦν	νοῦς
genitive	νοῦ	νῶν
dative	νῷ	νοῖς

Third declension

The third declension group includes masculine, feminine and neuter nouns. It is an athematic declension that lacks the standard thematic vowels of the two thematic declensions above. This results in varied and often complex phonemic interactions between stem and ending, especially so between adjacent consonants, that often make these nouns appear to be highly irregular compared to their straightforward thematic counterparts.

These nouns in the nominative singular end with the vowels α, ι, υ, ω or with the consonants ν, ρ, ς (ξ, ψ). They form the genitive case with -ος, ως or -ους.

Third-declension nouns have one, two, or three stems, unlike first- and second-declension nouns, which always have only one stem. Each stem is used in different case-and-number forms. In nouns with two stems, the stem with the long vowel is called the strong stem, while the stem with the short vowel is called the weak stem. The strong stem is found at the nominative singular, and the weak stem in the genitive singular.

• ἡγεμών (long vowel, strong stem: nominative singular)

  ἡγεμόνος (short vowel, weak stem: genitive singular)

Endings

The masculine and feminine nominative singular ordinarily ends in -ς, but has no ending in some nouns whose stems end in -ν- and -ντ-, and all nouns in -ρ: ἡγεμών, ἀκτίς (from *ἀκτίν-ς), γέρων (from *γέρωντ), γίγας (from *γίγαντ-ς), ῥήτωρ. The neuter nominative, accusative, and vocative singular always has no ending.

The ᾱ of the accusative singular and plural was originally a syllabic ν. The accusative singular ending -ᾱ appears after Proto-Greek consonants, and is much more common than -ν, because almost all third-declension stems end in a consonant. When a Proto-Greek consonant was lost (ϝ, ι̯, σ), -ᾱ appears after a vowel, and may be lengthened to ᾱ: βασιλέᾱ. The ending ν appears after the vowels υ and ι: ἰσχύν, πόλιν. The ending -νς always changes to -ᾱς, except in the accusative plural of ἰχθύς, where it lengthens the preceding υ by compensatory lengthening, yielding ἰχθῦς.

singular masc., fem. neut. nominative -ς, — — vocative —, -ς accusative -ᾰ, -ν genitive -ος dative -ι

dual masc., fem. neut. nominative -ε accusative vocative genitive -οιν dative

plural masc., fem. neut. nominative -ες -ᾰ vocative accusative -ᾰς, -νς genitive -ων dative -σι(ν)

Consonant-stems

These nouns end in -ν, -ρ, -ς (-ξ, -ψ). Based on the last letter of the stem, they are divided into two categories:

The mute-stem nouns have stems ending in -κ-, -γ-, -χ- (velar-stem nouns), -π-, -β-, -φ- (labial-stem nouns), -τ-, -δ-, -θ- (dental-stem nouns).

The semi mute-stem nouns have stems ending in -ν- (nasal-stem nouns), -λ-, -ρ- (liquid-stem nouns), -σ- (sibilant-stem nouns).

Nominative singular -ς and dative plural -σι cause pronunciation or spelling changes, depending on the consonant at the end of the stem.

	consonant at end of stem	nominative singular, dative plural
no consonant	—	-ς, -σι
dental	τ, δ, θ	-ς, -σι
velar	κ, γ, χ	-ξ, -ξι
labial	π, β, φ	-ψ, -ψι

Velar- and labial-stems

In the nominative singular and dative plural, the velars κ, γ, χ combined with σ are written as ξ, and the labials π, β, φ combined with σ are written as ψ.

	masc.
	κορακ- "raven"		γῡπ- "vulture"
	sg.	pl.	sg.	pl.
nominative	κόραξ	κόρακες	γύψ	γῦπες
vocative
accusative	κόρακα	κόρακας	γῦπα	γῦπας
genitive	κόρακος	κοράκων	γυπός	γυπῶν
dative	κόρακι	κόραξι	γυπί	γυψί

Dental- and nasal-stems

Stems in t

In the nominative singular and dative plural, a dental τ, δ, θ before σ is lost: τάπης, not τάπητς.

	masc.
	ταπητ- "floor"
	sg.	pl.
nominative	τάπης	τάπητες
vocative
accusative	τάπητα	τάπητας
genitive	τάπητος	ταπήτων
dative	τάπητι	τάπησι

If a noun is not accented on the last syllable and ends in -ις, -ης, or -υς, it often has an accusative singular in -ν and a vocative with no ending.

• ἡ χάρις, Πάρνης, κόρυς

  τὴν χάριν, Πάρνην, κόρυν (accusative)

  ὦ χάρι, Πάρνη, κόρυ (vocative)

Single-stems in nt

In the nominative singular and dative plural, ντ before σ is lost, and the previous vowel is lengthened by compensatory lengthening. In the vocative singular, final -τ is lost, as Ancient Greek words cannot end in stops.

	masc.
	γιγαντ- "giant"
	Singular	Plural
nominative	γίγας	γίγαντες
vocative	γίγαν
accusative	γίγαντα	γίγαντας
genitive	γίγαντος	γιγάντων
dative	γίγαντι	γίγᾱσι

When a noun is accented on the last syllable, the vocative singular is identical to the nominative:

• ὁ ἰμάς

  ὦ ἰμάς (vocative)

Double-stems in nt

These nouns have a weak stem in -οντ- and a strong stem in -ωντ-. The strong stem is used only in the nominative singular. The vocative singular is the weak stem without an ending. In both the nominative and vocative singular, the final τ disappears. In the dative plural, the σ in the ending causes the ντ to disappear, and the ο is lengthened to ου by compensatory lengthening.

	masc.
	γερων(τ)-, γεροντ- "old man"
	sg.	pl.
nominative	γέρων	γέροντες
vocative	γέρον
accusative	γέροντα	γέροντας
genitive	γέροντος	γερόντων
dative	γέροντι	γέρουσι

Stems in at

In these nouns, the stem originally ended in -ν̥τ- (with syllabic n), which changed to -ατ- in Greek. In the nominative singular, the final -τ disappeared.

	neut.
	κτηματ- "property"
	sg.	pl.
nominative	κτῆμα	κτήματα
vocative
accusative
genitive	κτήματος	κτημάτων
dative	κτήματι	κτήμασι

Single-stems in an, en, in, on

Some nouns have stems ending in -ν-. The nominative singular may end in -ς, causing compensatory lengthening, or have no ending.

	fem.
	ἀκτιν- beam
	sg.	pl.
nominative	ἀκτίς	ἀκτῖνες
vocative
accusative	ἀκτῖνα	ἀκτῖνας
genitive	ἀκτῖνος	ἀκτίνων
dative	ἀκτῖνι	ἀκτῖσι

Double-stems in en, on

Some nouns have a strong stem in -ην-, -ων- and a weak stem in -εν-, -ον-. The nominative singular is the only form with the strong stem. Nouns of this class that are not accented on the last syllable use the weak stem without an ending for the vocative singular.

• ὁ γείτων

  ὦ γεῖτον (vocative)

	masc.		fem.
	ἡγεμων-, ηγεμον- "leader "		ἀδην-, αδεν- "gland "
	Singular	Plural	Singular	Plural
nominative	ἡγεμών	ἡγεμόνες	ἀδήν	ἀδένες
vocative
accusative	ἡγεμόνα	ἡγεμόνας	ἀδένα	ἀδένας
genitive	ἡγεμόνος	ἡγεμόνων	ἀδένος	ἀδένων
dative	ἡγεμόνι	ἡγεμόσι	ἀδένι	ἀδέσι

Liquid-stems

Liquid-stems have stems ending in -λ- or -ρ-. Unlike mute-stems, these nouns do not change in spelling or pronunciation when the dative plural ending -σι is added.

Single-stems in er, or

Some nouns end in -ηρ, -ωρ and take the endings without any sound changes.

	masc.
	κλητηρ- "usher"
	sg.	pl.
nominative	κλητήρ	κλητῆρες
vocative
accusative	κλητῆρα	κλητῆρας
genitive	κλητῆρος	κλητήρων
dative	κλητῆρι	κλητῆρσι

Double-stems in er, or

Some nouns have a nominative singular in -ηρ, -ωρ. The stem for the rest of the forms ends in -ερ-, -ορ-. Nouns in this class that are not accented on the last syllable use the weak stem without an ending for the vocative singular.

	masc.
	ῥητωρ-, ῥητορ- "orator"
	sg.	pl.
nominative	ῥήτωρ	ῥήτορες
vocative	ῥῆτορ
accusative	ῥήτορα	ῥήτορας
genitive	ῥήτορος	ῥητόρων
dative	ῥήτορι	ῥήτορσι

Triple-stems in er

Some nouns have a strong stem in -ηρ in the nominative singular, a middle stem in -ερ- in other forms, and a weak stem in -ρ(α)- in yet other forms. The ᾱ in the dative plural was added for ease of pronunciation; the original form ended in -ρσι.

These include ὁ πατήρ "father", ἡ μήτηρ "mother", ἡ θυγάτηρ "daughter", ἡ γαστήρ "stomach", ἡ Δημήτηρ "Demeter", ὁ ἀνήρ "man".

The first three and γαστήρ use the weak stem in the genitive and dative singular and in the dative plural. The rest use the weak stem in the genitive, dative, and accusative singular and in the plural.

The vocative singular is usually the middle stem without an ending and accent on the first syllable. The exception is γαστήρ:

• ἡ γαστήρ

  ὦ γαστήρ (vocative)

	masc.
	πατηρ-, πατερ-, πατρ(α)- father
	sg.	pl.
nominative	πατήρ	πατέρες
vocative	πάτερ
accusative	πατέρα	πατέρας
genitive	πατρός	πατέρων
dative	πατρί	πατράσι

S-stems

Nouns in all three genders have stems ending in -εσ- or -οσ-. But in most cases, the σ was lost after being debuccalized to /h/, so for the most part the stems appear to actually end in -ε- -ο-. In Attic, but not Ionic, the ε or ο is contracted with the vowel of the ending. When σ combines with the -σι of the dative plural, the double σσ is simplified to single σ.

Masculines in es

There are several masculine proper names with nominative singulars in -ης and stems in -εσ-. The vocative singular is the bare stem without an ending.

	Σωκρατε(σ)- Socrates
	sg.
nominative	Σωκράτης
vocative	Σώκρατες
accusative	Σωκράτη
genitive	Σωκράτους
dative	Σωκράτει

Feminines in os

There are a few feminines with nominative singulars in -ως and stems in -οσ-.

	fem.
	αἰδωσ-, αἰδο(σ)- shame
	sg.
nominative	αἰδώς
vocative
accusative	αἰδῶ
genitive	αἰδοῦς
dative	αἰδοῖ

Neuters in es

Some neuter nouns have nominative, accusative, and vocative singulars in -ος, and stems in -εσ-.

	βελοσ-, βελε(σ)- "missile"
	sg.	pl.
nominative	βέλος	βέλη
vocative
accusative
genitive	βέλους	βελῶν
dative	βέλει	βέλεσι

Vowel-stems

These nouns end with ι, υ, ευ, αυ, ου, ω.

Stems in long o

These take the endings without sound changes.

• nom.: ὁ ἥρως (hḗrōs - "hero"), gen.: τοῦ ἥρωος (hḗrōοs), voc.: ὦ ἥρως (hḗrōs) etc., nom.: οἱ ἥρωες (hḗrōes), gen.: τῶν ἡρώων (hērṓōn) etc.

Single-stems in u

Because these nouns have a stem ending in -υ-, the accusative singular appears as -υν rather than -υα, and the accusative plural changes by compensatory lengthening from -υνς to -ῡς.

	masc./fem.
	ἰχθυ- "fish"
	sg.	pl.
nominative	ἰχθύς	ἰχθύες
vocative	ἰχθύ
accusative	ἰχθύν	ἰχθῦς
genitive	ἰχθύος	ἰχθύων
dative	ἰχθύϊ	ἰχθύσι

Triple-stems in i or u

There are many feminine nouns in -ις, and a few masculine nouns in -υς, and one neuter noun: ἄστυ "town".

One stem is in -ι- or -υ-, another is in -ει- or -ευ-, and a third is in -ηι- or -ηυ-. But these stems underwent sound changes, so that they are no longer obvious. Before a vowel, the ι or υ in the second and third stem became the semivowel ι̯ or ϝ, and was lost. The long-vowel stem in the genitive singular was shortened, and the vowel in the ending lengthened (quantitative metathesis). Therefore, there appear to be two stems, ending in ι/υ and ε.

	feminine
	πολι-, πολε(ι̯)-, πόλη(ι̯)- "city"
	sg.	pl.
nominative	πόλις	πόλεις
vocative	πόλι
accusative	πόλιν
genitive	πόλεως	πόλεων
dative	πόλει	πόλεσι

Stems in eu, au, ou

The nouns in -ευς have two stems: one with short ε, another with long η. Both originally ended with digamma, which by the time of Classical Greek had either vanished or changed to υ. Thus the stems end in -ε(υ)-, from *-εϝ-, and -η-, from *-ηϝ-. In Attic Greek the η of the stem underwent quantitative metathesis with the vowel of the ending—the switching of their lengths. This is the origin of the -ως, -ᾱ, and ᾱς of the forms based on the stem in -η-.

	masculine
	βασιληυ- "king"
	sg.	pl.
nominative	βασιλεύς	βασιλεῖς
vocative	βασιλεῦ
accusative	βασιλέᾱ	βασιλέᾱς
genitive	βασιλέως	βασιλέων
dative	βασιλεῖ	βασιλεῦσι

The nouns with a vowel before the -εύς often contract the final ε of the stem (either original or from quantitative metathesis of η), which disappears into the following ω and ᾱ of the genitive and accusative singular and plural. As is the rule, the vowel resulting from contraction takes a circumflex:

• nom.: ἁλιεύς (halieús), gen.: ἁλιέως (haliéōs) and ἁλιῶς (haliôs), ἁλιέων (haliéōn) and ἁλιῶν (haliôn), acc.: ἁλιέα (haliéa) and ἁλιᾶ (haliâ), ἁλιέας (haliéas) and ἁλιᾶς (haliâs).

Stems in oi

Stems in -οι- end in -ω in the nominative singular. The ι becomes the semivowel ι̯ and is lost, except in the vocative singular. There are no plural forms; when the plural does appear, it follows the second declension. The rest of the cases are formed by contraction.

	feminine
	ἠχω-, ἠχο(ι̯)- "echo"
	sg.
nominative	ἠχώ
accusative
vocative	ἠχοῖ
genitive	ἠχοῦς
dative	ἠχοῖ

Derivation

Diminutive suffixes

New nouns may be formed by suffix addition. Sometimes suffixes are added on top of each other:

• βύβλος búblos "papyrus"
  • βιβλίον biblíon "book"
  • βιβλάριον, βιβλιάριον, βιβλαρίδιον, βιβλιδάριον "small scroll"^[9]

    biblárion, bibliárion, biblarídion, biblidárion

  • βιβλίδιον biblídion "petition"

References

1. The Inflectional Accent in Indo-European. Paul Kiparsky. Language. Vol. 49, No. 4 (Dec., 1973), pp. 794-849. Linguistic Society of America.
2. Herbert Weir Smyth, Greek Grammar, par. 214 D: dialectal first-declension forms
3. Smyth, par. 219: short-a first declension
4. Smyth, par. 221: suffix -ι̯ᾰ in short-a first declension
5. Smyth, par. 112: κι̯, χι̯ to ττ (σσ)
6. Smyth, par. 111: "epenthesis" of ι̯ suffixed to an, on, ar, or
7. Smyth, par. 37: compensatory lengthening
8. Smyth, par. 225: genitive singular of masculine first declension
9. βιβλάριον. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project