Prepositions of Time in English: Basic Rules and Examples

Let me teach you prepositions of time.

As an English teacher with over a decade of experience, I can tell you that prepositions of time are often some of the trickiest little words in the English language. They’re small but mighty.

One minute, you think you understand how to use “in,” “on,” and “at,” and the next, you find yourself tangled in confusion over whether you should say “on Monday” or “at Monday.” (Spoiler alert: it’s “on Monday.”)

Prepositions of time—words like “in,” “on,” “at,” and “during”—are essential in everyday communication.

Whether you’re scheduling a meeting, planning a vacation, or telling someone about your day, they help you convey when something happens.

Yet, despite their frequency, they can trip us up.

Understanding these little time markers will not only make you sound more fluent, but it’ll also boost your confidence in both spoken and written English.

So, let’s dive in and untangle these little time-related puzzles together!

This topic is part of our English Grammar for English learners.

Table of Contents

The Basics: What Are Prepositions of Time?

Before we get into the nitty-gritty, let’s take a step back and understand what prepositions of time are.

Simply put, these are words that link nouns (or pronouns) to other words in a sentence, specifically to indicate when an action or event takes place.

In other words, prepositions of time answer the question, “When?”

Here are the most common prepositions of time you’ll encounter:

In
On
At
During
Before
After
By

Each of these has its own rules and uses, and once you understand them, you’ll find it much easier to express when things happen.

“In,” “On,” and “At”: The Big Three

These three prepositions are the building blocks of time-related sentences, so let’s break them down one by one.

1. In: A General Marker of Time

“In” is used to refer to larger periods of time, like months, years, decades, and centuries.

Think of it as the go-to preposition for broader time frames.

Examples:

In the morning – I drink coffee in the morning.
In January – We’re going on vacation in January.
In 2025 – I’m moving to New York in 2025.
In the 21st century – Technology has advanced a lot in the 21st century.

2. On: Specific Days or Dates

On is used when referring to specific days, dates, or holidays. It’s a little more pinpointed than “in” and is great for when you want to talk about individual days or particular moments.

Examples:

On Monday – I have a meeting on Monday.
On Christmas Day – We always have a big family dinner on Christmas Day.
On my birthday – I like to relax on my birthday.

3. At: Exact Moments or Small Time Frames

At is used to express an exact moment or point in time. This is the go-to preposition when you’re referring to specific times of the day, holidays, or a particular hour.

Examples:

At 7:00 PM – Let’s meet at 7:00 PM.
At noon – I usually take lunch at noon.
At night – I love walking at night.
At the weekend – We’ll go hiking at the weekend.

Less Common Prepositions of Time

While “in,” “on,” and “at” are the most common, English also uses other prepositions of time that have specific functions. These include “before,” “after,” “during,” and “by.”

4. During: When Something Happens Throughout a Period

“During” refers to the entirety of a time frame. It focuses on the duration of an event within a specific period. You can use it to describe something happening while a particular event is happening.

Examples:

During the meeting – I had to leave during the meeting.
During the summer – We usually travel during the summer.
During my childhood – I was very active during my childhood.

5. Before: Prior to a Time

“Before” indicates that something happens prior to a specific time or event. It can refer to any point in the past, or any point in the future that precedes a set moment.

Examples:

Before lunch – I like to go for a walk before lunch.
Before the party – I need to finish my work before the party starts.
Before 8:00 AM – I always wake up before 8:00 AM.

6. After: Following a Time

“After” is the opposite of “before.” It means something happens later than a specific event or moment.

Examples:

After work – I’m going to the gym after work.
After the concert – We can go for dinner after the concert.
After lunch – I usually take a short nap after lunch.

7. By: Up to a Specific Time

“By” indicates that something will happen at or before a certain time. It’s perfect when you want to set a deadline or express that something must happen before a particular moment.

Examples:

By 5:00 PM – I need to finish this report by 5:00 PM.
By next week – The project should be completed by next week.
By the end of the month – We need to make a decision by the end of the month.

How to Remember the Differences

So, how do you keep these prepositions straight? I get it. Sometimes, it can feel like a puzzle. But here’s a simple trick:

“In” is for larger periods: years, months, seasons.
“On” is for specific days: dates, days of the week.
“At” is for exact times or moments: hours, holidays.

Think of it as a scale, with “in” being the broadest, followed by “on,” and then “at” being the most specific.

Common Mistakes with Prepositions of Time

Even experienced speakers sometimes trip over these little prepositions.

Here are a few common mistakes I’ve seen in my classroom and how to avoid them:

1. Mixing Up “In” and “On”

Wrong: I’ll see you in Monday.
Right: I’ll see you on Monday.

Remember: “In” is for months, years, and seasons, while “on” is for days and dates.

2. Using “At” for Larger Time Frames

Wrong: I’m visiting Paris in the summer at 2025.
Right: I’m visiting Paris in the summer in 2025.

“On” and “in” often get mixed up in situations like this, but they each have specific roles.

3. Forgetting to Use “During” for Ongoing Events

Wrong: We will travel in the winter.
Right: We will travel during the winter.

Remember, “during” is used for the entire duration of a period.

Wrapping Up

Mastering prepositions of time might seem like a small detail, but it makes a big difference in your communication.

They help you express when things happen with precision and clarity, whether you’re telling a story, making plans, or sharing your schedule.

Here’s a quick recap of the key takeaways:

In is for broad time frames (months, years, seasons).
On is for specific days and dates.
At is for exact moments or specific times.
Use “during” to talk about something happening throughout a period of time.
“Before” and “after” are for relative times.
“By” helps you set deadlines or indicate a limit.

The best way to get comfortable with these is through practice.

Don’t be afraid to make mistakes—remember, even experienced speakers sometimes slip up.

Keep using them, and before long, you’ll be a pro at expressing time in English.

Happy learning, and I hope this helps you feel more confident using prepositions of time in your conversations and writing!

FAQs on Prepositions of Time

1. What are prepositions of time in English grammar?
Prepositions of time are small words that show when something happens. Examples include in, on, at, before, after, during, by.

2. What is the difference between “in,” “on,” and “at” in prepositions of time?

In = broad periods (months, years, centuries). Example: I was born in 2000.
On = specific days or dates. Example: We met on Friday.
At = exact time or point. Example: Let’s meet at 6 PM.

3. How do you use “during” in a sentence?
“During” is used to show that something happens in the course of a specific time period.
Example: I slept during the movie.

4. What is the difference between “by” and “until”?

By = no later than a specific time (deadline). Example: Submit the report by Monday.
Until = continuing up to a time. Example: I worked until midnight.

5. What are common mistakes with prepositions of time?

Saying ❌ in Monday instead of ✔️ on Monday.
Using ❌ at 2025 instead of ✔️ in 2025.
Forgetting “during” for longer periods.

6. Can I use prepositions of time in questions?
Yes! Examples:

What are you doing on Sunday?
Will you finish the project by tomorrow?
Did she call you at night?

7. Why are prepositions of time important in English?
They make your communication clear and precise. Without them, sentences can be confusing. Example:
❌ I’ll meet you Monday.
✔️ I’ll meet you on Monday.

Prepositions of Time in English: Basic Rules and Examples

The Basics: What Are Prepositions of Time?