The ablative case is a form of a noun or adjective that may express a number of different functions, including motion or means. It is found in inflected languages, those in which a word's grammatical role within a sentence is determined by the form of the word, usually a prefix or a suffix. Words in the ablative case are often objects of prepositions, but they may also serve a variety of other functions, depending on the language.
Latin and Greek are the inflected languages most commonly familiar in the Western world, although Albanian, Sanskrit, Turkish, and a number of other languages are also inflected. The functions of the Greek ablative case were absorbed into the genitive or dative cases by the time of Homer, but both Classical and Ecclesiastical Latin contain an ablative case. A Latin ablative noun or adjective takes its form depending on the word's declension. Latin has five declensions, or sets of endings, that are used to differentiate word cases. A first-declension Latin ablative, for instance, will end with -ā, while second declension ablatives will end with -ō.
Since the ablative case most often expresses something regarding location or motion, it is usually the object of a preposition, which defines the specific relation of the noun to the rest of the sentence. For example, the Latin prepositional phrase "ab agricolā" means "away from the field." The object, "agricolā," is in the ablative case. This sentence may contain other words in the ablative case as well. In English, these are functions that would generally be expressed by an adverbial phrase, such as "by means of."
Adjectives modifying ablative nouns will also be in the ablative case, but this does not mean that the noun and adjective will always have the same ending. Like nouns, adjectives in an inflected language are divided according to declension. If the noun and the adjective belong to the same declension — that is, they use the same set of endings — they will most often have the same ending. On the other hand, a noun in the first declension and an adjective in the third declension will probably not have the same ending.