📍 Grammar: Prepositions – in, on, at
1ère Bac Sciences et Technologies Elécriques STE
📌 Introduction
We use in, on, at to talk about time and place. Choosing the right preposition is key to clear communication.
Science Tip: “The experiment starts at 9 AM on Monday in the lab.”
⏰ Prepositions of Time
Rules for Time
at → specific time: at 9 AM, at noon, at midnight
on → days and dates: on Monday, on June 5th, on my birthday
in → months, years, centuries, long periods: in June, in 2025, in the morning
Example: “The biology class starts at 10:30 on Friday in September.”
📍 Prepositions of Place
Rules for Place
in → inside a space: in the classroom, in Morocco, in the box
on → surface contact: on the desk, on the wall, on the page
at → specific point: at the door, at the lab, at the top
Example: “The experiment is in the lab. The results are written on the board. Meet me at the entrance.”
✅ Exercise 1: Choose “in”, “on”, or “at”
The class starts ___ 8:30 AM.
✅ Exercise 2: Complete the Sentence
We have a test ___ Friday.
✅ Exercise 3: Time Preposition
My birthday is ___ July.
✅ Exercise 4: Place Preposition
The book is ___ the shelf.
✅ Exercise 5: Correct the Mistake
“I was at school in 8:00.” →
✅ Exercise 6: Science Context
The results will be announced ___ the science fair.
✅ Exercise 7: Fill in the Blank
We study Biology ___ the morning.
✅ Exercise 8: Real-Life Use
Meet me ___ the library entrance.
✅ Exercise 9: Sentence Completion
The diagram is drawn ___ the whiteboard.
✅ Exercise 10: Write a Sentence
Write a sentence using “in”, “on”, and “at”:
