Uses of the ablative

Prolegomena

One of the results of English having lost its inflection for nouns is a dependence on prepositions, which are little words that relate one noun or pronoun to another noun or pronoun.

He is a friend of the family.

In this instance, the prepositional phrase indicates possession. Here are several others:

Of course, we don't stop to think how often we use prepositions, nor do we bother, even if we do stop to think, to codify the ways in which we so use them. Consider, for instance, the last three examples above. Each uses the preposition "with," but we're saying quite different things in each one; the first tells us the manner in which Mr. Barnes conducts, the second explains the instrument with which he conducts (or, in this case, which he does not need), and the third conveys the person with whom he conducts.

An inflected language like Latin needs not depend so heavily upon prepositions to link nouns to one another sensibly; the difference in cases itself can show relations between nouns. Of course, Latin has prepositions--lots of them, governing the accusative and ablative cases--but the bottom line is this: the role played by prepositional phrases in English may be performed in Latin by the simple use of certain case in a certain context. But, because this is so, it is useful to distinguish these specific uses of certain cases (they are called "constructions"), and to give them names. This chapter of the Oxford Latin Course adds a few more of constructions, but it seems also to be a good time to summarize, in one place, most of the common and important ablative constructions. Some, in fact, require a preposition in Latin; several do not; one can go either way.

Basic Ablative Constructions