English Adverbs vs. Prepositions

Prepositions are sometimes confused with adverbs and vice versa. Many prepositions can function as adverbs, but this occurs only when there is no object tied to the preposition. Adverbs are words that answer the questions when, how, where, and to what extent or degree an action is done (time, manner, place, degree).

Here are some prepositions that are often used as adverbs:

above          across          after          before          behind
below          by                 down         in                 inside
of                 off                on              outside        over
through        to                 up              with             without

Prepositions can sometimes have implied objects that are understood from the context, even if they are not written or said. For example:

     Ralph waited outside the restaurant for a few minutes, and finally he went in. 

The word outside is a locational preposition, even though in other sentences it can be an adverb by itself. The adverb in has no object following it, but it is implied that it is in the restaurant, which means “in” is still a preposition.

A similar example to the one above illustrates the use of prepositions as adverbs:

     Ralph waited outside for a few minutes before he went inside.

Because it is not clear where “inside” or “outside” are, these general terms are adverbs of place (no implied object). Here are a few more examples:

     Paul got up and closed the door.
     He looked at the sky above.

In each example, the italicized words are prepositions without objects that indicate general direction, and so are considered adverbs. More recently, however, adverbs of place that look like prepositions and have implied objects are considered part of the category “locational prepositions.”