Prepositions

Simple explanation

A preposition is a small word that tells us the relationship between two things — usually where something is or when something happens.

Think of prepositions as the glue that connects a noun to the rest of the sentence.

Why it matters

Wrong prepositions are one of the most common mistakes in English. "I am good in math" sounds wrong. "I am good at math" sounds right. The meaning is the same, but the preposition tells a fluent listener whether you know English well.

In, On, At — for Place

Preposition	Use it for	Examples
in	Enclosed spaces, cities, countries	in the room, in Mumbai, in India
on	Surfaces, floors, roads	on the table, on the 3rd floor, on MG Road
at	A specific point or location	at the door, at the bus stop, at home

In, On, At — for Time

Preposition	Use it for	Examples
in	Months, years, seasons, parts of day	in May, in 2024, in the morning
on	Days, specific dates	on Monday, on 15 August
at	Exact clock times, specific moments	at 9 a.m., at midnight, at noon

Wrong vs right

The phrase good at is a fixed expression. Skill or ability always uses at, not in.

Daily life usage

1. "The keys are on the table." (surface)
2. "She lives in Bangalore." (city)
3. "The meeting is at 10 a.m." (exact time)
4. "We are flying on Friday." (day of week)
5. "It gets cold in December." (month)

Other common prepositions

These come up every day and are worth knowing by feel, not by rule:

• to — direction: I am going to the office.
• from — origin: She is from Chennai.
• with — together: I came with my team.
• for — purpose or duration: I waited for an hour.
• about — topic: Let's talk about the project.
• between — two things: Choose between these two options.

Practice quiz

Quick summary

• In — enclosed spaces, cities, countries, months, years.
• On — surfaces, days, specific dates.
• At — exact points in place or time, clock times.
• Good at, not good in — skill always uses at.