Preposition is “a word or group of words that is used with a noun, pronoun, or noun phrase to show direction, location, or time, or to introduce an object”.
“The ball is ON the table” the preposition ON shows location.
“I will be ready IN two hours” the preposition IN shows time.
“You should climb OVER the wall” the preposition OVER shows direction.
Prepositions are called the biggest small words in English language. They are small but they are important to the meaning of the sentences.
Using prepositions correctly takes some time and practice.
Avoiding unnecessary preposition usage is also important. If the meaning of sentence is not changing when you do not use a preposition, then the preposition is not needed.
WRONG: We talked about the experiment.
CORRECT: We talked the experiment.
WRONG: He entered into the kitchen.
CORRECT: He entered the kitchen.
You can find prepositions of place, position. direction, time and other important prepositions with examples down below.
Also check prepositions with adjectives list here