What is a preposition?
A preposition is a small word that shows how one thing is connected to another. Prepositions often tell where, when or which way.
The cat is on the sofa. The cat is under the sofa. The cat is behind the sofa.
Only one word changed each time, but the picture changed completely. That is the power of prepositions.
The "box" trick
Picture a box and a mouse. Any word that can tell where the mouse is compared to the box is probably a preposition:
in the box, on the box, under the box, beside the box, behind the box, around the box, inside the box, near the box, between the boxes, over the box, through the box
This trick works for place prepositions. Some prepositions, like of, for, about and during, do not fit the box but are still prepositions.
Prepositional phrases
A preposition never works alone. It begins a prepositional phrase, which ends with a noun or pronoun called the object of the preposition.
| Preposition | Object | Phrase |
|---|---|---|
| across | the street | across the street |
| after | lunch | after lunch |
| with | my sister | with my sister |
| to | them | to them |
Prepositional phrases add detail. They often answer where? when? how? which one?
The girl with the red hat sat on the bench after school.
Three main kinds
Prepositions of place
A preposition of place tells where something is: in, on, at, under, over, beside, between, behind, in front of, next to, among, against.
- in for inside a space: in the car, in Canada
- on for a surface: on the table, on the wall
- at for a specific point: at the door, at school
Prepositions of time
A preposition of time tells when: at, on, in, before, after, during, since, until, by.
- at for clock times: at 3:00, at noon
- on for days and dates: on Monday, on May 5
- in for months, years, seasons and parts of the day: in July, in 2025, in winter, in the morning
Prepositions of direction
A preposition of direction shows movement: to, into, onto, toward, through, across, up, down, past, around.
The ball rolled into the pond. We walked across the bridge toward the castle.
Prepositions or adverbs?
Some words can be prepositions or adverbs. If the word has an object after it, it is a preposition. If it stands alone, it is an adverb.
- She ran outside the gym. (preposition; object: the gym)
- She ran outside. (adverb; no object)
Pronouns after prepositions
The object of a preposition is always an object pronoun: me, him, her, us, them.
This gift is for him. Sit between Ava and me. (not between Ava and I)
Worked examples
Example 1: Find the prepositional phrases. During the storm, the dog hid under the bed.
During the storm, under the bed.
Example 2: Choose in, on or at. My birthday is ___ June. The party is ___ Saturday ___ 2:00.
→ in June, on Saturday, at 2:00.
Example 3: Preposition or adverb? Please come in.
→ Adverb (no object follows in).
Common mistakes
- I’ll meet you on 4:00. ✗ → at 4:00 ✓
- He jumped in the pool is fine in casual speech, but into the pool is clearer for movement.
- between you and I ✗ → between you and me ✓
- Extra prepositions: Where is it at? → Where is it?
Try it yourself
- Underline the prepositions: The squirrel ran up the tree and across the roof.
- Fill in: We go skating ___ winter, usually ___ Sunday mornings.
- Name the object of the preposition: I went to the store with Grandma.
- Write a sentence with three prepositional phrases.
Answers: 1. up, across. 2. in, on. 3. the store and Grandma. 4. Answers will vary, for example After dinner, we walked along the river to the park.
Tip for families
Play "Where’s the teddy?" Hide a stuffed animal and give clues using only prepositional phrases: "It’s under something, behind a door, near the window." Then switch roles.
Quick recap
- Prepositions show relationships of place, time and direction.
- They begin prepositional phrases that end in a noun or pronoun.
- Use at for times, on for days and in for months and years.
- Use object pronouns after prepositions.