The third declension

Declension

In linguistics, declension is the inflection of nouns, pronouns, adjectives, and articles to indicate number , case , and gender...

is a category of noun

Noun

In linguistics, a noun is a member of a large, open lexical category whose members can occur as the main word in the subject of a clause, the object of a verb, or the object of a preposition .Lexical categories are defined in terms of how their members combine with other kinds of...

s in Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 and Greek

Ancient Greek

Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

 with broadly similar case

Grammatical case

In grammar, the case of a noun or pronoun is an inflectional form that indicates its grammatical function in a phrase, clause, or sentence. For example, a pronoun may play the role of subject , of direct object , or of possessor...

 formation — diverse stems

Word stem

In linguistics, a stem is a part of a word. The term is used with slightly different meanings.In one usage, a stem is a form to which affixes can be attached. Thus, in this usage, the English word friendships contains the stem friend, to which the derivational suffix -ship is attached to form a new...

, but similar endings

Suffix

In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns or adjectives, and verb endings, which form the conjugation of verbs...

. In contrast with the first-

First declension

The first declension is a category of mostly feminine nouns in Latin and Ancient Greek with the defining feature of a long ā...

 and second-declension

Second declension

The second declension is a category of nouns in Latin and Greek with similar case formation. In particular, these nouns are thematic, with an original o in most of their forms. In Classical Latin the short o of the nominative and accusative singular became u.Both Latin and Greek have two basic...

 endings, those of the third declension lack a theme vowel (a or o/u in the first and second declensions) and so are called athematic.

One distinguishing feature of third-declension nouns is a genitive

Genitive case

In grammar, genitive is the grammatical case that marks a noun as modifying another noun...

 singular ending of a short vowel and s: Latin rēg-is "of a king" Greek χειρ-ός (cheir-ós) "of a hand". Another is a dative

Dative case

The dative case is a grammatical case generally used to indicate the noun to whom something is given, as in "George gave Jamie a drink"....

 singular ending of i (short i in Greek, long ī in Latin): rēg-ī "for a king"; χειρ-ί (cheir-í) "for, with the hand".

Many third declension nouns, unlike first- or second-declension nouns, show different stems depending on case and number — usually one stem for the nominative

Nominative case

The nominative case is one of the grammatical cases of a noun or other part of speech, which generally marks the subject of a verb or the predicate noun or predicate adjective, as opposed to its object or other verb arguments...

 singular, and another for the rest of the cases, though some Greek nouns have three stems. Greek stems are often formed by ablaut: Latin homō "person" and homin-ēs "people"; Greek πατήρ (patēr’) "father", πατρ-ός (patr-ós) "of a father", and πατέρ-ες (patér-es), "fathers".

A subcategory within both the Latin and Greek third declension is nouns with consonant

Consonant

In articulatory phonetics, a consonant is a speech sound that is articulated with complete or partial closure of the vocal tract. Examples are , pronounced with the lips; , pronounced with the front of the tongue; , pronounced with the back of the tongue; , pronounced in the throat; and ,...

 stems. These, unlike all first- and second-declension nouns, end in a consonant. Often the consonant at the beginning of certain endings undergoes a sound change with the consonant of the stem: Latin rēx "king", from rēg-s (compare the earlier-mentioned rēgis); πούς (poús) "foot", and Attic dative plural ποσί (posí) "on foot" from πόδ-ς (pód-s) and ποδ-σί (pod-sí).

Greek third declension nouns with vowel endings

Other Greek nouns whose stems in the earliest Greek (notably Mycenaean) ended in ι (i) or υ (u), and j (English consonantal y) or ϝ

Digamma

Digamma is an archaic letter of the Greek alphabet which originally stood for the sound /w/ and later remained in use only as a numeral symbol for the number "6"...

 (digamma; English w) in e-grade, have in later Greek undergone sound changes that markedly distinguish them from run-of-the-mill third-declension nouns. In particular, the stems with j or ϝ lose this sound, and in some cases the preceding vowel is lengthened by compensatory lengthening

Compensatory lengthening

Compensatory lengthening in phonology and historical linguistics is the lengthening of a vowel sound that happens upon the loss of a following consonant, usually in the syllable coda...

. In Attic

Attic Greek

Attic Greek is the prestige dialect of Ancient Greek that was spoken in Attica, which includes Athens. Of the ancient dialects, it is the most similar to later Greek, and is the standard form of the language studied in courses of "Ancient Greek". It is sometimes included in Ionic.- Origin and range...

, if there is a short vowel adjacent in the ending, the two vowels switch their lengths by quantitative metathesis

Quantitative metathesis

Quantitative metathesis is a specific form of metathesis or transposition involving quantity or vowel length...

. Illustrative of the process is the development of the genitive singular of βασιλεύς (basileús), "king", πόλις (pólis), "city", and ἄστυ (ástu), "town":

early Greek *βασιλῆϝ-ος → Homeric

Homeric Greek

Homeric Greek is the form of the Greek language that was used by Homer in the Iliad and Odyssey. It is an archaic version of Ionic Greek, with admixtures from certain other dialects, such as Aeolic Greek. It later served as the basis of Epic Greek, the language of epic poetry, typically in...

 βασιλῆος → Attic βασιλέωςhttp://www.ccel.org/s/smyth/grammar/html/smyth_2g_uni.htm

early Greek *πόλεj-oς → Homeric πόληος → Attic πόλεωςhttp://www.ibiblio.org/bgreek/test-archives/html4/1997-12/22468.html

early Greek *ϝάστηϝ-ος → *ἄστηος → Attic ἄστεως

*basilēw-os → basilēos → basiléōs

*póley-es → pólēos → póleōs

*wástēw-os → *ástēos → ásteōs

Further reading

For specific information on the third declension as it appears in Latin and Greek, and paradigm

Paradigm

The word paradigm has been used in science to describe distinct concepts. It comes from Greek "παράδειγμα" , "pattern, example, sample" from the verb "παραδείκνυμι" , "exhibit, represent, expose" and that from "παρά" , "beside, beyond" + "δείκνυμι" , "to show, to point out".The original Greek...

s of nouns belonging to the different subcategories, see the appropriate sections in Latin declension and Ancient Greek nouns.