Definition of prepositions

Prepositions are grammatical words that have no inherent meaning like a noun or verb would.  Instead, they contribute to the grammatical meaning of the sentence. What preposition a writer should use depends upon the context of the sentence. The prepositions at, on, and in are the most common, but, of, for, and about are also discussed in the following pages.

The most common uses of prepositions are to show location. However, in English, location can be literal or metaphorical. The 3 main types of preposition uses for at, on, and in are:

  • Spatial/Physical
  • Time
  • Metaphorical

Spatial (physical) preposition uses

Spatial prepositions are used to show a physical location. How specific the location is depends upon the preposition that you choose to use.


The preposition “at” is used to show a general point or place.

  • We met at Starbucks for coffee.

Using “at” here is somewhat ambiguous, as “we” could have met outside of Starbucks, inside of Starbucks, or in the Starbucks parking lot.  However, what is relevant is that “we” met somewhere near Starbucks.

  • I ran into Jonathon at work today.


The preposition “on” is used to show location when connected to a surface without walls or specific boundaries.

  • She put the glass on the table.
  • We walked on the dirt road for miles.


The preposition “in” is used for locations where boundaries are present (such as walls) that define being “inside.”

  • While I was in New York I bought a sweater.

A big city like New York is often seen as having large buildings that can “encase” you if you are in the city.

  • I was in Starbucks when I bought a coffee.

Because of the use of “in,” it is assumed that the individual is literally inside the walls of Starbucks. Contrast this with the use of “at.”

Time proposition uses


The preposition “at” is used to describe a small unit of time, such as hours or minutes.

  • We will meet at nine o' clock on Saturday.

“At” is used to show the specific, small unit of time of nine o' clock.

  • At 10:32 in the morning, my car was hit.


The preposition “on” is used to describe a restricted amount of time, which includes dates and days of the week.

  • We will meet at nine o’ clock on Saturday.

Here, we are talking about a day of the week, so we use the preposition “on” since this preposition is used for more lengthy time references than “at.”

  • The party will be on June 22nd.


The preposition “in” is used to describe a broad and/or lengthy unit of time. This includes: years, seasons and months.

  • We can plan the event for some time in October.

Here, “in” is used because we are talking about a more extensive point in time than hours or even days. We are talking about an entire month.

  • In 1776, the U.S. declared independence.

Metaphorical time preposition uses

Prepositional use in metaphors is a complicated aspect of prepositions. To help the process, think of abstract ideas as being a physical box. Some examples of abstract ideas are: love, danger, difficulties, state of being, and words. Imagine each noun as being its own separate box that people can step into, walk through, or get out of.

Here is a list of examples of how these prepositions and nouns can function in a sentence:

  • Jimmy and Kelly are in love.
  • Sarah is going through a difficult time right now.
  • I’m trying to get out of a bad situation at work.
  • If you can’t express yourself in words then how can I understand you?
  • I’m in an awful mood.

In this way, prepositions are used to show location in metaphorical circumstances. Moods and abstract situations are often thought of as something that a person is metaphorically inside of, thus the preposition “in” is used. Metaphorical prepositions are tricky and can take practice to master, but remembering to think of each scenario as being something that a person is “inside of” can help the process.

The preposition “of”

The preposition “of” is somewhat unique because it does not rely heavily on location, as other prepositions do. The preposition “of” is used for a number of reasons:

As an integrative or relationship function.

  • The roof of the green house was orange.

The preposition “of” shows the relationship between the green house and the roof. The roof is part of the green house. 

  • Peter was in the army, but wasn’t of it.

The preposition “of” shows that even though Peter was physically in the army, he did not have a special relationship/allegiance to the army.

Showing possession

  • James is the boyfriend of Veronica.

The preposition “of” shows that, in a way, James belongs to Veronica.

  • The remark of the judges was not good.

The preposition “of” shows how the remark belongs to the judges.

Noun and descriptor integration.

  • Robert was glad the beast of a man was his friend.

Instead of using the phrase “the man that was like a beast,” by inserting the preposition “of” we can turn it into the “beast of a man,” with “beast” describing the kind of man that “he” was. 

Note: this is a somewhat specialized use of the preposition “of" and cannot be used with every description word and noun.

The preposition “for”

The preposition “for” is uses for grammatical purposes when expressing purpose or belonging of something. It is generally used in two specific ways:

To show purpose

  • Sara went to the store for milk.

Here, the preposition “for” is showing what Sara was going to the store to get. 

  • For goodness’ sake, Henry, stop being so strange!

The preposition “for” in this sentence, shows that Henry should stop being strange for the reason of goodness.

To show a length of time

  • Marcus will be gone for at least one week.

Here, the preposition “for” is showing an expanse of time that Marcus will be gone, which is one week. 

  • The cookies will be baking for about thirty minutes.

The preposition “for” is a connecting word that shows the cookies will be banking for a certain span of time.

The preposition “about”

The preposition “about” is used to show the relationship between a subject and a topic, a subject and a location, or a subject and time.

Use as a topic

  • Jennifer knows a lot about languages.

Here, the preposition “about” connects Jennifer’s knowledge to the topic, languages. 

  • The story about the elephant had all of us laughing.

Again, here “about” is signaling the topic of the story, which was the elephant.

Use for location

  • The girl went about the city.

Here, the preposition “about” is showing a location concerning where the girl is. She is in the city, likely in motion walking around in it.

Use for time

  • The party will start about 8:00.

Here, the preposition “about” is used to show an approximate time that the party will start.

  • Sharon is going to leave for class at about 7:30.

“About” is used to show an approximate time that Sharon is going to leave for class.