A preposition is a part of speech that expresses a relation between a noun or pronoun (as the object in a sentence or phrase) and another word. Examples in English are ‘in’, ‘into’, ‘to’, ‘before’, ‘from’, ‘near’, ‘within’, ‘above’. There are quite a few, and a number of English prepositions are translated into Latin using the same word, e.g. inter can mean ‘amid’, ‘among’ or ‘between’.

There are also compound prepositions consisting of two or three words in English that are represented by one or two words in Latin. Examples are ‘except for’ (praeter), ‘next to’ (juxta), ‘out of’ (a, ab, ex) and ‘up to’ (usque ad)

In Latin, a preposition governs the case of the noun or pronoun that follows it. Some take the accusative, others the ablative (see below). In the Vocabulary we indicate the case taken by each.

A few take either, depending on the meaning. Those used in botanical Latin in this context are in, subter and super. A general rule is that when some motion into or towards is meant they take the accusative, but when the motion is from or out of they take the ablative.