I-Stems
Historical **i-stems** include important nouns in **-ις, -εως**, such as **πόλις, πόλεως**, **πίστις, πίστεως**, and **κρίσις, κρίσεως**. Their paradigms show stem allomorphy rather than one invariant visible vowel: the **nominative and accusative singular** preserve an i-grade, while several oblique forms show an **ε-grade**; plural forms such as **πόλεις** reflect class-specific historical development rather than a simple i-grade rule.
For **πόλις**, compare **πόλις, πόλιν** with **πόλεως, πόλει, πόλεσι(ν)**. The genitive **-εως** is historically associated with **quantitative metathesis**; the dative **-ει** reflects contraction of the ε-grade stem with -ι. The ε-grade is a stem allomorph within the i-stem paradigm, not an independent ε-declension.
U-Stems
**U-stems** end in -υ. A common NT u-stem is **ἰχθύς** ('fish'), which retains υ in its oblique forms: nom. **ἰχθύς**, gen. **ἰχθύος**, dat. **ἰχθύϊ**, acc. **ἰχθύν**, pl. nom. **ἰχθύες**, acc. **ἰχθύας** (cf. Matt 14:17). Not every u-stem keeps υ: some (e.g. πῆχυς, gen. πήχεως) show the 'mixed' ε/-εως pattern. Note that **πῦρ** ('fire') is an r-stem, not a u-stem, and **ἄστυ** ('city') — a Classical ε/-εως-type u-stem with oblique stem ἀστε(υ)- (gen. ἄστεως) — does not occur in the NT.
**Matt 14:17** — οἱ δὲ **λέγουσιν** αὐτῷ· Οὐκ **ἔχομεν** ὧδε εἰ μὴ πέντε **ἄρτους** καὶ δύο **ἰχθύας** ('…we have nothing here except five loaves and two **fish**') — ἰχθύας = acc. pl. m.
Mixed I/U-Stems
Some historical i- and u-stem paradigms are traditionally described as **mixed** because different stem grades/allomorphs appear in different parts of the paradigm. 'Mixed' therefore means **structured stem alternation**, not uncertainty about the noun's class.
In the πόλις-type i-stem, the genitive **-εως** reflects historical quantitative metathesis, while the dative **-ει** reflects contraction of the ε-grade stem plus -ι. Similar mixed behavior in u-stem paradigms must be described class by class. The appearance of ε in an oblique form is not by itself evidence for an independent ε-stem declension.
ΕΥ-Stems
Stems in **-ευ** form an important third-declension class: **βασιλεύς, βασιλέως, βασιλεῖ, βασιλέα, βασιλεῦ**; plural **βασιλεῖς, βασιλέων, βασιλεῦσι(ν)**. Other NT examples include **ἱερεύς, ἀρχιερεύς, γραμματεύς**, and **γονεύς**.
Different forms reflect different historical processes. The genitive **βασιλέως** is conventionally explained through older digamma loss together with **quantitative metathesis**; the dative **βασιλεῖ** involves genuine vowel contraction. GOLD therefore does not label every change in the ευ paradigm simply 'contraction'. Classification follows the actual paradigm; nouns from other declensions must not be inserted into the ευ-stem class.
**Matt 2:1** — **Τοῦ δὲ Ἰησοῦ γεννηθέντος** ἐν **Βηθλεὲμ** τῆς Ἰουδαίας ἐν **ἡμέραις** **Ἡρῴδου τοῦ βασιλέως** ('…in the days of Herod **the king**') — βασιλέως = gen. sg.
**Matt 2:2** — …ποῦ **ἐστιν ὁ τεχθεὶς βασιλεὺς τῶν Ἰουδαίων**; ('Where is the one born **king** of the Jews?') — βασιλεὺς = nom. sg. (predicate nominative in apposition).
βασιλεύς-Type Nouns
The **βασιλεύς** paradigm is the model for all ευ-stems. It includes many NT titles: **βασιλεύς** (king), **ἱερεύς** (priest), **ἀρχιερεύς** (high priest), **γραμματεύς** (scribe). Learn βασιλεύς, βασιλέως and the rest follow.
πόλις-Type Nouns
**πόλις** (city) is the model i-stem. Other i-stems of the same 'mixed' type, with genitive in -εως: **πίστις** (faith, gen. πίστεως), **κρίσις** (judgment, gen. κρίσεως), **δύναμις** (power, gen. δυνάμεως), **ἀνάστασις** (resurrection, gen. ἀναστάσεως).
**John 3:19** — αὕτη δέ ἐστιν ἡ **κρίσις** ὅτι τὸ φῶς ἐλήλυθεν εἰς τὸν κόσμον… ('And this is the **judgment**, that the light has come into the world…') — κρίσις = nom. sg. f. (i-stem of the 'mixed' type; gen. κρίσεως).
**Eph 1:19** — …κατὰ τὴν **ἐνέργειαν** τοῦ **κράτους** τῆς **ἰσχύος** αὐτοῦ ('…according to the working of the **power** of his **might**').
πίστις-Type Nouns
**πίστις** ('faith') belongs to the i-stem class: the stem vowel appears as **ι** in the nominative/accusative singular (**πίστις**, **πίστιν**) and as **ε** in the oblique forms (**πίστεως**, **πίστει**). Full pattern: nom. **πίστις**, gen. **πίστεως**, dat. **πίστει**, acc. **πίστιν**, pl. nom. **πίστεις**, gen. **πίστεων**, dat. **πίστεσι(ν)**, acc. **πίστεις**. 'Faith' is one of the most important theological nouns in the NT.
**Eph 2:8** — τῇ γὰρ χάριτί ἐστε σεσῳσμένοι **διὰ πίστεως** ('For by grace you are saved **through faith**') — πίστεως = gen. sg.
**Heb 11:1** — **Ἔστιν δὲ πίστις** ἐλπιζομένων ὑπόστασις … ('Now **faith** is the assurance of things hoped for …').
ναῦς and Related Historical Forms
**ναῦς** ('ship') is an archaic stem (ναυ-) with diphthong αυ. It appears only rarely in the NT (Acts 27 — Paul's sea voyage). Its paradigm preserves old Indo-European forms and is learned mainly for reading Acts 27-28.
Irregular Vowel-Stem Nouns
Some third-declension vowel and diphthong nouns retain idiosyncratic forms or inherited stem alternations. Learn the **nominative together with the genitive**, identify the declensional subtype, and then use the class-specific paradigm. The genitive is an important diagnostic form, but no single surface-string rule resolves every third-declension class.
Paradigms
I-Stem: πόλις, πόλεως ('city')
The model i-stem, 'mixed' pattern: -ι in nom./acc. sg.; -εω- in gen. sg. (quantitative metathesis) and -ει in dat. sg. (contraction); -εις/-εων/-εσιν in plural.
| Case | Singular (πόλις, 'city') | Plural |
| Nom. | πόλις nom. sg. f. city | πόλεις nom. pl. |
|---|---|---|
| Gen. | πόλεως | πόλεων |
| Dat. | πόλει | πόλεσι(ν) |
| Acc. | πόλιν | πόλεις |
| Voc. | πόλι | πόλεις |
ΕΥ-Stem: βασιλεύς, βασιλέως ('king')
The model ευ-stem. Note the gen. sg. -έως (from older *-ῆ(ϝ)ος with quantitative metathesis), dat. sg. -εῖ (contracted), acc. sg. -έα, and the **common dat. pl. -εῦσι(ν)**.
| Case | Singular (βασιλεύς, 'king') | Plural |
| Nom. | βασιλεύς nom. sg. m. king | βασιλεῖς nom. pl. |
|---|---|---|
| Gen. | βασιλέως | βασιλέων |
| Dat. | βασιλεῖ | βασιλεῦσι(ν) |
| Acc. | βασιλέα | βασιλεῖς |
| Voc. | βασιλεῦ | βασιλεῖς |
Chapter glossary
- πόλις — city
polis
noun
Third-declension f., i-stem (mixed pattern); gen. πόλεως.- βασιλεύς — king
basileus
noun
Third-declension m., ευ-stem; gen. βασιλέως; cf. βασιλεία (kingdom).- ἰχθύς — fish
ichthys
noun
Third-declension m., u-stem; acrostic Ἰησοῦς Χριστὸς Θεοῦ Υἱὸς Σωτήρ in early Christian art.- πίστις — faith, trust, belief
pistis
noun
Third-declension f., i-stem of the 'mixed' type (gen. -εως); gen. πίστεως; central Pauline word.- κρίσις — judgment
krisis
noun
Third-declension feminine **i-stem** in -ις, genitive **κρίσεως**. It belongs to the -ις/-εως system and is not a historical sigma stem.- δύναμις — power, miracle
dynamis
noun
Third-declension f., i-stem of the 'mixed' type; gen. δυνάμεως; power of God / miracles.- ἀρχιερεύς — high priest, chief priest
archiereus
noun
Third-declension m., ευ-stem; gen. ἀρχιερέως; frequent in Passion narratives.- γραμματεύς — scribe, clerk
grammateus
noun
Third-declension m., ευ-stem; gen. γραμματέως.- — i-stem
noun
Third-declension stem ending in -ι (πόλις, κρίσις), often with the 'mixed' pattern (gen. -εως).- — ε-stem
noun
A descriptive label for an **ε-grade / ε-stem allomorph** within certain third-declension vowel-stem paradigms. It must be tied to the noun's fuller i-, u-, or related class and does not constitute one independent 'ε declension'.- — ευ-stem
noun
Third-declension stem ending in -ευ (βασιλεύς, ἱερεύς, ἀρχιερεύς).