In Latin and Greek, as in other inflected languages, there are multiple forms for each noun. One form is used as the singular subject; another as the plural, generally differentiated by "s". So much we also have in English, but in inflected languages there are other forms, too. These other forms, plus the nominative (subject), are known as cases. What distinguishes the various forms from one another in Latin and Greek is the ending on the noun, which goes on the stem. For this reason, they are called case endings. In Latin and Greek there is a set of endings for the singular and another for the plural. (Greek also has a dual case.) Latin has five complete sets of case endings. These are known as the five declensions.
The case endings are translated into English with the help of prepositions.
More on Latin Cases
Urbs, a 3rd declension noun, is the nominative case singular of the Latin noun for city.
Stem: urb-.
Urbis is the genitive case singular, translated as "of the city".
The dative case singular is urbi, translated as "to/for the city".
The accusative case singular is urbem. Urbem can be the direct object of a verb or the object of a preposition.
The ablative is urbe, which can be translated by various prepositions, but might be translated "with the city".
The plural of urbs also has case endings for the nominative, genitive, and accusative that are distinct. The ablative and dative plural are the same.
