The third declension

A noun you cannot recognise from its first form

John 1:14 begins:

The Word became flesh and made His dwelling among us.

John 1:14

"Flesh" is σὰρξ (sarx). It says what the Word became, and "become", like "to be" in the lesson on εἰμί, links two nominatives, so σάρξ is nominative too. It is feminine.

Now look at the end of the same verse, "from the Father". The word for father is πατήρ, yet the verse has πατρός (patros). Meeting πατρός for the first time, you might not realise it is the same word as πατήρ, because the vowel between τ and ρ has dropped out in the genitive.

That is the signature of the third declension. In the second declension (λόγος, θεός) the stem stays visible and only the ending changes. In the third, the stem is hidden in the nominative and shows in the genitive. The genitive of σάρξ is σαρκός, so the stem is σαρκ-, and the ξ of the nominative is κ and σ fused together. This looks strange, but the goal of the lesson is to recognise these words, not to produce them.

Learning the endings by eye

Because the genitive shows the stem, dictionaries often give two forms, "nominative / genitive". Here are the words of this lesson.

Neuter nouns in -μα (πνεῦμα, ὄνομα, σῶμα) are very common. Their genitive ends in -ματος, and their plural nominative and accusative in -ματα. Nouns like πίστις usually have an unusual genitive in -εως (χάρις, with χάριτος, is an exception), which is worth recognising on its own.

The endings that attach to the stem are these.

You do not need to memorise the whole grid. The three that pay off most are genitive -ος, dative -ι and plural genitive -ων. For the rest the panel will tell you. When a strange form turns up, tap it, read the case and number the panel gives, and check the lexicon form. Trusting the label is quicker and more reliable than trying to decode the form yourself.

Reading real verses

The rest of John 1:14 has more of this family. In "full of grace and truth", χάριτος (charitos) is the genitive of χάρις, with its stem χαριτ- showing. χάρις occurs about 155 times in the New Testament. In Ephesians 2:8, "through faith", πίστις appears as the genitive πίστεως (pisteōs), the case demanded by the preposition διά "through". πίστις is very common, about 240 times.

For it is by grace you have been saved through faith, and this not from yourselves; it is the gift of God,

Ephesians 2:8

In the baptismal command, two third-declension genitives stand side by side.

baptizing them in the name of the Father and of the Son and of the Holy Spirit,

Matthew 28:19

πατρὸς is the genitive of πατήρ, dependent on the accusative ὄνομα (onoma), "name", which occurs about 229 times. And πνεύματος (pneumatos) is the genitive of πνεῦμα. Notice that the article before πατρός, τοῦ, is masculine, while the one before πνεύματος, τοῦ, is neuter. The gender of a third-declension noun is hard to read off its ending, so the article and adjective are your guide. πατήρ occurs about 413 times and πνεῦμα about 373.

Vocatives are often a shortened stem. The first words of the Lord's Prayer are πάτερ (pater), the vocative of πατήρ: the long η has simply shortened to ε. "O Father" is all you need to see. Here is a plural as well. In 1 John 1:1, "touched with our own hands" is literally "our hands touched", and the subject is χεῖρες (cheires), with the plural nominative ending -ες. χείρ occurs about 175 times.

Finally, the body. In 1 Corinthians 12:27, "you are the body of Christ", σῶμα (sōma) is a neuter -μα noun in the nominative. Remember that neuters have the same form in nominative and accusative. σῶμα occurs about 142 times.

Summary

Third-declension nouns hide their stem in the nominative and show it in the genitive, so σάρξ and σαρκός, πατήρ and πατρός are one word each. The endings worth recognising are genitive -ος, dative -ι and plural genitive -ων, and the neuter -μα nouns have the genitive -ματος. When a form is strange, trust the panel's case label and lexicon form. In the next lesson, participles follow these same endings in the masculine and neuter.

Words in this lesson

• πνεῦμαpneumaspirit/breath: spirit373 times in the NT
• πατήρpatērfather413 times in the NT
• σάρξsarxflesh147 times in the NT
• χάριςcharisgrace155 times in the NT
• πίστιςpistisfaith240 times in the NT
• ὄνομαonomaname229 times in the NT
• σῶμαsōmabody142 times in the NT
• χείρcheirhand175 times in the NT

Practice