What is a Preposition?
There are over 100 prepositions in the English language. A preposition links nouns, pronouns, and phrases to other words in a sentence. A preposition usually indicates time or place in regards to the object (the word or phrase being introduced by the preposition).
A Point in Time
At, in, and on are prepositions of time.
At denotes a specific time; in is used for months, years, or any extended period of time; and on is used for days or dates.
His flight leaves at 7 PM.
That store is not open at night.
They always go camping in the summer.
That movie came out in 1997.
Her birthday is in March.
He has a test on Monday.
He was born on May 6.
Next, Last, Every, This
We also use the prepositions next, last, every, and this:
I will see you next week. (Not on next week.)
I was on vacation last April. (Not in last April.)
I will call you this afternoon. (Not in this afternoon.)
We get together every Christmas. (Not at every Christmas.)
In, inside, on, and at are prepositions of place.
In refers to the point itself; inside expresses something which is contained; on talks about a surface; and at refers to a general vicinity.
There is a fly in this room.
There is a letter inside the envelope.
The book is on the table.
She is waiting at home.
Higher or Lower Than a Point
We use the prepositions over and above to express an object being higher than a point:
He hit the ball over the fence.
The mirror is above the sink.
We use the prepositions under, underneath, beneath, and below to express an object being lower than a point.
Some animals burrow under the ground.
The sock was underneath the blanket.
We sat in the shade beneath the trees.
From the plane, the people below us looked like ants.
Close to a Point
We use the prepositions near, by, next to, between, among, opposite to express an object’s proximity to another object or point.
Their house was near the school.
He read his book by the trees.
He sat between the two girls.
There were a few flowers among the weeds.
She sat opposite her friend.
Introducing Objects of Verbs
At: smile, laugh, look
She smiled at the boy.
They laughed at the comedian.
The dog was looking at the cat.
Of: consist, smell, approve
The project consists of many parts.
I don’t like the smell of cigarettes.
The man did not approve of his daughter’s new boyfriend.
Of (or about): dream, think
She dreams of being a movie star one day.
He was thinking about taking a vacation.
For: call, hope, wait, watch
Did someone call for me?
She always hoped for the best.
I was waiting for you to arrive.
Watch for the train.
Ending a Sentence with a Preposition
It is a common myth that you cannot end a sentence with a preposition. There are many cases in which you can; in these cases, if you left out the preposition, your sentence would no longer make sense.
The first example is very common: What did you step on?
You cannot leave out the preposition on; you could, if you wanted to, rearrange the order of the sentence and instead ask, “On what did you step?” But “What did you step on?” is correct, and generally the way you will hear most people ask that question.
You do not, however, end a sentence with a preposition if it makes the sentence sound redundant.
For example: “Where are you at?” is redundant. “Where are you?” is sufficient enough.
Some phrasal verbs – verbs made up of multiple words, one of which is a preposition – are okay to use: Cheer up, run over, log on, and leave off.