A preposition is a part of speech which enables you to describe relationships between people or things.
Normally you will use a preposition to describe where something is. We would also use a preposition to tell someone when and where another person is:
David is on the bus now; he should arrive at 6pm.
There are a lot of prepositions, at least over a hundred. They are never used alone, and must be used to describe the relationship between a noun or pronoun with the rest of the sentence.
Rules for prepositions
Many people argue that a preposition should not be used at the end of a sentence. Although this rule is often broken in spoken English:
I'll see you around.
There is often doubt about which preposition is the correct one to use in a sentence. Days and times are often a stumbling block in the use of prepositions:
I'm meeting my boyfriend on Monday.
Let's meet up at five o'clock.
There is no simple explanation for the difference in usage of 'on' and 'at'. All you can do is to decide which sounds right or to have a good dictionary to hand.
You can also use more than one preposition in a sentence:
Everyone is going to the party except for Jane.
Do not use a preposition for the subject of a sentence, but only for the object of a sentence. If in doubt, think of the preposition as coming before the object as per the below sentence:
He rode his bike down the hill.
This way of using a preposition is what's known as a simple preposition. Here are three more examples of the use of simple prepositions:
We went out for a short car ride.
She took me to the Manchester Christmas markets.
I fell asleep during the movie.
If there are several nouns in your sentence then there are rules governing the prepositions you can use. For places I tend to think of how you would travel the item to ensure I use the correct preposition:
I climbed down the mountain.
I ran through the field.
So, if your sentence must have two different prepositions as in the two previous examples, then you would stick to this rule:
She ran down the hill and through forest to get home.
You can also use one preposition to describe two places in one action. The preposition needs to be before the first noun:
He drove at high speed passing through a forest and a park.
As we mentioned earlier, more than one preposition can be used. It is often necessary to put two or more prepositions to make your sentence clear. These prepositions, when put together, act as a single piece which we refer to as complex prepositions. The use of complex prepositions is the same as simple prepositions in that we must put them before nouns or pronouns in a sentence:
I'll meet you in front of the town hall.
I'll travel next month along with Peter.
A place and time for prepositions
As stated earlier, there are over one hundred prepositions you can use. To state the time of something occurring you can use the following prepositions: at, by, since, for, after, during and before. Notice in the below examples that all the prepositions are before the object of the sentence:
I have to leave by midnight.
Can you pay me during the lunch hour?
She arrived after the meeting.
When using prepositions to describe places, you can use the following prepositions: under, off, on, through, around, over and down:
The building is over on fourth street.
The parking garage is under the building.
She lives at number seven down the street.
It is possible to use prepositions in a similar manner to adjectives and adverbs. An adjective is a word that describe the qualities of an item such as
The blue car.
An adverb describes an action that a thing or person takes:
He swam deeply in the lake.
If we consider the below sentence:
John found a gold bar in the safe.
The above prepositional phrase is providing more information about the gold bar and is describing it using the preposition 'in'. The preposition 'in' is acting like an adjective which makes the sentence a prepositional phrase.
In the next sentence we can see a preposition acting like an adverb:
The sled raced down the hill.
The preposition 'down' describes the movement of the sled and is therefore acting like an adverb in what is known as a prepositional phrase.
When using prepositions take your time to check the usage is correct. Get used to looking through an English dictionary as this will make the meaning of a preposition very clear. I tend to use the Collins English dictionary. If I use it to look up the preposition 'around' then the dictionary will clearly label it as a preposition but also as an adverb. There is also a short description of how to use the word as a preposition and adverb.
Don't forget to also use a thesaurus to replace words, which appear too often, in your text to make changes that make your writing varied and more interesting to read.
Article by Mark Jones