# Koine Greek/5. Declining 1st and 2nd Declension Nouns
## Grammar
### Second Declension

Second declension nouns and adjectives end in -ο, and their declension follows the pattern given below. To decline a second-declension noun, we take the ending in the table and add it to the stem (which always ends in -ο). If a vowel is underlined, then we replace the ο in the stem with that vowel.
| Case | Singular | Plural |
| Nominative | ς | ι |
| Genitive | υ | ων |
| Dative | ῳ | ις |
| Accusative | ν | υς |
| Vocative | ε | ι |
When we give a noun, we typically give the singular nominative form of the noun, as well as the ending for the singular genitive case.
Example: Here is the declension chart for the noun κύριος, -υ, which means "lord"
| Case | Singular | Plural |
| Nominative | κύριος | κύριοι |
| Genitive | κύριου | κύριων |
| Dative | κύριῳ | κύριοις |
| Accusative | κύριον | κύριους |
| Vocative | κύριε | κύριοι |
Here is the declension chart for second declension neuter nouns:
| Case | Singular | Plural |
| Nominative | ν | α |
| Genitive | υ | ων |
| Dative | ῳ | ις |
| Accusative | ν | α |
| Vocative | ν | α |
Example: Here is the declension chart for the noun τέκνον, -υ, which means "child".
| Case | Singular | Plural |
| Nominative | τέκνον | τέκνα |
| Genitive | τέκνου | τέκνων |
| Dative | τέκνῳ | τέκνοις |
| Accusative | τέκνον | τέκνα |
| Vocative | τέκνον | τέκνα |
Most second declension nouns are either masculine or neuter, although there are feminine second declension nouns as well.

### First Declension

First declension nouns end with α or η, and are typically feminine (although there are masculine ones as well). They fall under two slightly different patterns that differ only in the singular genitive and dative.
Pattern 1 (at *, we add an ι-improper diphthong to the vowel: α -> ᾳ, η -> ῃ)
| Case | Singular | Plural |
| Nominative | - | αι |
| Genitive | ς | ων |
| Dative | * | αις |
| Accusative | ν | ας |
| Vocative | - | αι |
Example: καρδία, -ας (Heart)
| Case | Singular | Plural |
| Nominative | καρδία | καρδίαι |
| Genitive | καρδίας | καρδίων |
| Dative | καρδίᾳ | καρδίαις |
| Accusative | καρδίαν | καρδίας |
| Vocative | καρδία | καρδίαι |
Example: φωνή, -ής (Voice)
| Case | Singular | Plural |
| Nominative | φωνή | φωναί |
| Genitive | φωνής | φωνών |
| Dative | φωνῄ | φωναίς |
| Accusative | φωνήν | φωνάς |
| Vocative | φωνή | φωναί |
Pattern 2: Virtually identical, except we change α to η in the singular genitive and dative cases.
| Case | Singular | Plural |
| Nominative | - | αι |
| Genitive | ης | ων |
| Dative | ῃ | αις |
| Accusative | ν | ας |
| Vocative | - | αι |
Example: δόξα, -ης (Glory)
| Case | Singular | Plural |
| Nominative | δόξα | δόξαι |
| Genitive | δόξης | δόξων |
| Dative | δόξῃ | δόξαις |
| Accusative | δόξαν | δόξας |
| Vocative | δόξα | δόξαι |

### Grand patterns

* The genitive plural of all declensions in Greek (all nouns, pronouns, adjectives, verb participles, basically anything that can decline) end in ων.
* The accusative and nominative of all neuter declensions in Greek are the same.
* In all declensions, the dative case contains an ι, perhaps as an improper diphthong.

## Vocabulary
### Second Declension Masculine

* ἄγγελος, -ου: angel, messenger
* ἀδελφός, -ου: brother (Philadelphia, the city of brotherly love)
* ἄνθρωπος, -ου: man (anthropology, the study of humankind)
* θεός, -ου: god (theology, the study of the divine)
* κόσμος, -ου: world (cosmology, the study of the universe; cosmopolitan, worldly)
* κύριος, -ου: lord (kyrie eleison, "Lord have mercy", the beginning of the Mass)
* λόγος, -ου: that which is said, or thought. Translated as word, but has deep meanings in philosophy (-logy, the study of -; logic)
* νόμος, -ου: law (astronomy, the law of the stars)
* οὐρανός, -ου: heaven (Uranus, the Greek god of the sky)
* υἱός, -ου: son
* ἀπόστολος, -ου: apostle, literally, one that is sent
* διδάσκαλος, -ου: teacher (didactic, intending to teach)

### Second Declension Neuter

* ἔργον, -ου: work, deed (ergonomics)
* ἱερόν, -οῦ: temple (hierarchy, from ranking of angles, which derives from rule of the high priest)
* πρόσωπον, -ου: face
* τέκνον, -ου: child

### First Declension Feminine

* ἀλήθεια, -ας: truth
* ἁμαρτία, -ας: sin (hamartiology)
* βασιλεία, -ας: kingdom (basilica)
* ἡμέρα, -ας: day (ephemeral)
* καρδία, -ας: heart (cardiology)
* χαρά, -ας: grace (charity)
* γλῶσσα, -ης: tongue (glossary, polyglot)
* δόξα, -ης: glory (doxology)
* θάλασσα, -ης: sea (thalassic)
* ἀγάπη, -ης: love (agape)
* γῆ, -ῆς: earth, land, soil (geology)
* ζωή, -ῆς: life (zoology) .
* φωνή, -ῆς: sound, voice (telephone)
* ψυχή, -ῆς: soul (psychology)