Words that are sometimes prepositions can act as adverbs. A preposition requires an object. An adverb does not.
A single word acting as an adverb answers where, when, how or to what degree about the verb.
- If you want to see the eclipse, you will need to go outside.
OUTSIDE tells you where YOU WILL NEED TO GO.
NOTE: Without an object OUTSIDE is an adverb.
When the same word is a preposition, the entire prepositional phrase acts as an adverb modifying the verb.
- Dorothy colors outside the lines.
OUTSIDE THE LINES is an adverbial phrase and OUTSIDE is a preposition.
NOTE: LINES is the object of the preposition.
To determine whether a word is an adverb or a preposition, look at what follows the word. Is there a noun acting as an object of the word? In other words, is there a word that answers the question WHAT? about the word.
- It will be some time before his schedule settles down.
DOWN tells the reader WHERE the schedule settles. There is no object following it.
- Please sit down and listen.
DOWN tells the listener WHERE to SIT. There is no object telling him or her WHAT to SIT DOWN.
- One need only look down the roster to see the impact of so much travel.
ROSTER answers the question WHAT? about the word DOWN. One need only look down what? THE ROSTER. ROSTER is the object of the preposition DOWN.
Consider how many of these prepositions could be used as adverbs:
by way of
in addition to
in front of
in place of
|in regard to
in spite of
on account of