A preposition is a word that connects one thing with another, showing how they are related.
Some prepositions tell you about time.
For example:
"Many shops close on Sundays."
"It snows during the winter."
Take a look at the two sentences. They are similar; yet, they have different meanings. What is the difference?
'Throw it to him.'
'Throw it at him.'
As you can see the prepositions in each sentence are different. Here's how the prepositions change the meaning: