Prepositions are words that express the relation of a noun or pronoun to another word in the sentence. Prepositions show the relationships between things, people, and places.

Prepositions
 Using "On" Correctly
 In, On, At (Expressions of Time)
 In, On, At (Expressions of Place)
Prepositions Exercises
 Expressions of Time: Exercise 1
 Expressions of Place Exercise 1
 Expressions of Place Exercise 2
Links on Prepositions
 Prepositions Showing Location (Writing Den-Digital Education Network)