Nouns, pronouns, and adjectives are declined (verbs are conjugated), and a given pattern is called a declension.
Adjectives are of two kinds: those like bonus, bona, bonum 'good' use first-declension endings for the feminine, and second-declension for masculine and neuter.
These latter decline in a similar way to the first and second noun declensions, but there are differences; for example the genitive singular ends in -īus or -ius instead of -ī or -ae.
A complete Latin noun declension consists of up to seven grammatical cases: nominative, vocative, accusative, genitive, dative, ablative and locative.
However, the locative is limited to a few nouns: generally names of cities, small islands and a few other words.
This traditional order was formerly used in England, such as in The School and University Eton Latin Grammar (1861).
They are declined irregularly in the singular, but sometimes treated as native Latin nouns, e.g. nominative athlēta ('athlete') instead of the original athlētēs.
For full paradigm tables and more detailed information, see the Wiktionary appendix First declension.
There are several small groups of feminine exceptions, including names of gemstones, plants, trees, and some towns and cities.
The locative endings for the second declension are -ī (singular) and -īs (plural); Corinthī "at Corinth", Mediolānī "at Milan", and Philippīs "at Philippi".
[5] Nouns ending in -ius and -ium have a genitive singular in -ī in earlier Latin, which was regularized to -iī in the later language.
For example, the genitive and vocative singular Vergilī (from Vergilius) is pronounced Vergílī, with stress on the penult, even though it is short.
For example, socer, socerī ('father-in-law') keeps its e. However, the noun magister, magistrī ('(school)master') drops its e in the genitive singular.
The stem of a consonant-stem noun may be found from the genitive case by removing the ending -is.
The locative endings for the third declension are -ī or -e (singular) and -ibus (plural), as in rūrī 'in the country' and Trallibus 'at Tralles'.
[15] The accusative singular ending -im is found only in a few words: always in tussis 'cough', sitis 'thirst', Tiberis 'River Tiber'; usually in secūris 'axe', turris 'tower', puppis 'poop', febris 'fever'; occasionally in nāvis 'ship'.
[16] The ending -im is not found in any adjectives, even those that have a separate feminine such as celeris 'swift' or ācris 'keen',[17] or in any masculine common nouns.
Likewise, pater ('father'), māter ('mother'), frāter ('brother'), and parēns ('parent') violate the double-consonant rule.
Some nouns in -tāt-, such as cīvitās, cīvitātis 'city, community' can have either consonant-stem or i-stem genitive plural: cīvitātum or cīvitātium 'of the cities'.
The fourth declension is a group of nouns consisting of mostly masculine words such as flūctus, flūctūs m. ('wave') and portus, portūs m. ('port') with a few feminine exceptions, including manus, manūs f. ('hand') and domus, domūs f. ('house').
However, in practice, it is generally declined as a regular -us stem fourth declension noun, except for ablative singular -ō, accusative plural -ōs, and the use of the locative.
The genitive forms meī, tuī, nostrī, vestrī, suī are used as complements in certain grammatical constructions, whereas nostrum, vestrum are used with a partitive meaning ('[one] of us', '[one] of you').
[19] (& meus) The possessive adjective vester has an archaic variant, voster; similar to noster.
In accusative case, the forms mēmē and tētē exist as emphatic, but they are not widely used.
Relative, demonstrative and indefinite pronouns are generally declined like first and second declension adjectives, with the following differences: These differences characterize the pronominal declension, and a few special adjectives (tōtus 'whole', sōlus 'alone', ūnus 'one', nūllus 'no', alius 'another', alter 'another [of two]', etc.)
Adjectives (in the first and second as well as third declensions) that have masculine nominative singular forms ending in -er are slightly different.
Some third declension adjectives with two endings in -lis in the masculine–feminine nominative singular have irregular superlative forms.
Instead, magis ('more') and maximē ('most'), the comparative and superlative degrees of magnoperē ('much, greatly'), respectively, are used.
Ūnus, ūna, ūnum is declined like a first- and second-declension pronoun with -īus or -ius in the genitive, and -ī in the dative.
Both declensions derive from the Indo-European dual number, otherwise defunct in Latin, rather than the plural.