Is the word from a preposition?

Prepositions are words that show the relationship between a noun or pronoun (the object of the preposition) and another word in the sentence.

Here's an example:

* From the store, I bought a loaf of bread.

In this sentence, "from" shows the relationship between "store" (the object of the preposition) and "bought" (the verb). It tells us where the bread was bought.