Here's why:
* Location: Prepositions indicate where something is located. For example:
* "The book is on the table."
* "She lives in a small town."
* Relationship: Prepositions can also describe the relationship between things. For example:
* "He is with his friends."
* "The dog is under the table."
Some common prepositions include: on, in, at, under, over, beside, behind, before, after, between, among, to, from, with, without, by, for, etc.