The 1st Declension

Source: Oulton. N.R.R. 2010. So You Really Want To Learn Latin Book I Tenterden, Great Britain: Galore Park Publishing (1999).

Chapter II – Nouns of the 1st declension

Nouns like: “mēnsa, mensae, f. = Table”

In the same way that verbs in Latin have endings to show who is doing the verb, and when, nouns in Latin have endings to show what part the noun is playing in the sentence. As with verbs, nouns are divided up into groups, and these are called declensions. Noun of the first declension decline like mēnsa:

Singular
Nominative – mēnsa – [Table (subject)]
Vocative – mēnsa – [O table! (addressing)]
Accusative – mēnsam – [Table (object)]
Genitive – mēnsae – [Of a table]
Dative – mēnsae – [To or for a table]
Ablative – mēnsā – [By, with or from a table]

Plural
Nominative – mēnsae – [Tables (subject)]
Vocative – mēnsae – [O tables! (addressing)]
Accusative – mēnsās – [Tables (object)]
Genitive – mēnsārum – [Of the tables]
Dative – mēnsīs – [To or for the tables]
Ablative – mēnsīs – [By, with or from the tables]

The Six Cases

1. The Nominative case is used to show that the noun is the subject of the sentence, i.e. that the noun is the person doing the verb. E.g. ‘The girl loves the farmer’ = puella agricolam amat.
2. The Vocative case is used for addressing the noun. E.g. ‘O sailors, you love the island’ = nautae, īnsulam amātis.
3. The Accusative case is used to show that the noun is the object, i.e., the person or thing to which the verb is being done. E.g. ‘He loves the girl‘ = puellam amat.
4. The Genitive case is used for ‘of’. The genitive case is the possessive case. In English we either use the word ‘of’ or else we use an apostrophe. In Latin, the ‘possessor’ (i.e. the noun that is doing the possessing) is put into the genitive case and may come before or after the other noun. E.g. ‘The table of the farmer‘ / ‘The farmer’s table’ = mēnsa agricolae.
5. The Dative case is used for the indirect object and is generally translated with ‘to’ or ‘for’. E.g. ‘The farmer sings to the girl‘ = agricola puellae cantat.
6. The Ablative case is used for the instrument by means of which we do something. It is often translated by the words from, by or with, but (in the case of the latter two) only when these mean by means of. E.g. ‘They overcome the inhabitants by means of wisdom‘ = incolās sapientiā superant.

N.B. Latin has no definite or indefinite article. Thus mēnsa = table or the table or a table – the choice is yours.