Prepositions of Time

Prepositions are an essential part of speech that can sometimes confuse English learners due to their subtle but important distinctions. These small words help clarify the relationship between a noun (or pronoun) and other parts of the sentence, often indicating time, location, or direction. When it comes to prepositions of time, their primary role is to tell us when an event or action occurs.

In this article, we will focus on the most common prepositions of time: at, on, and in. While these prepositions all deal with time, they each serve different purposes, and understanding their distinctions is key to mastering their use in everyday communication.

What Are Prepositions of Time?

A preposition of time is a word used to indicate when an action or event takes place. These prepositions help us pinpoint specific moments or general periods in time. The three most commonly used prepositions of time are at, on, and in.

Though all three relate to time, they are not interchangeable. They are each used in specific contexts, depending on the exact nature of the time reference. Let’s explore each preposition in detail to understand how they are used effectively.

Usage of “At,” “On,” and “In”

The prepositions at, on, and in are commonly used to express time, but they differ significantly in their usage. It’s important to remember that these prepositions cannot be used interchangeably, as each one refers to a distinct time frame. Below, we will break down the proper contexts for each preposition.

At – Used for Specific Moments

The preposition at is used to indicate a precise point in time. It is typically employed when referring to exact hours, minutes, and moments. It’s also used in certain expressions that denote specific events or occasions.

Examples:

• Specific time:

  • At 5:00 PM – The meeting is scheduled at 5:00 PM.

  • At noon – I’ll see you at noon.

  • At midnight – The fireworks will start at midnight.

• Expressions of time:

  • At the moment – She is busy at the moment.

  • At the same time – They arrived at the same time.

  • At sunrise – We will leave at sunrise.

  • At sunset – The park looks beautiful at sunset.

At is used for time-related expressions that denote a specific instance or event.

On – Used for Days and Dates

The preposition on is used when referring to a specific day or date. It also applies to repeated events that happen on a certain day of the week.

Examples:

• Specific day:

  • On Monday – I will see you on Monday.

  • On Sunday – The picnic is planned on Sunday.

• Specific date:

  • On May 25th – My birthday is on May 25th.

  • On Christmas Eve – We usually celebrate on Christmas Eve.

• Repetitive days:

  • On weekdays – She works on weekdays.

  • On Saturdays – We go hiking on Saturdays.

On is used when the reference point is a particular day or a regular occurrence on a given day.

In – Used for Broader Time Periods

The preposition in is used to refer to larger time spans such as months, years, decades, and seasons. It helps convey a general time frame without pinpointing a specific day or hour.

Examples:

• Longer periods:

  • In December – We’re going to Paris in December.

  • In 2023 – They plan to move in 2023.

  • In the 21st century – Technology has evolved greatly in the 21st century.

• Seasons and months:

  • In winter – I love skiing in winter.

  • In summer – We go to the beach in summer.

• Times of the day:

  • In the morning – I like to drink coffee in the morning.

  • In the afternoon – She sleeps in the afternoon.

In is used to refer to broader time frames, such as seasons, months, and years, or when a specific time of the day is being discussed.

Prepositions of Time: A Quick Reference Table

Common Mistakes to Avoid with Prepositions of Time

Even though at, on, and in are widely used, many English learners make mistakes when choosing which one to use. Below are some common errors, along with explanations to help you avoid them.

1. Mixing Up ‘At’ and ‘In’

Many learners confuse at and in when referring to times of the day. While at is used for specific times (like hours), in is used for broader periods (like parts of the day).

Common Mistake:

• Incorrect: I will meet you in 3:00 PM.

• Correct: I will meet you at 3:00 PM.

Explanation:

When referring to an exact time (like an hour or minute), always use at.

2. Using ‘On’ for Months

Another common mistake is using on when referring to months or seasons. Instead, in should be used for these broader time periods.

Common Mistake:

• Incorrect: I am going to Italy on August.

• Correct: I am going to Italy in August.

Explanation:

Use in for months, years, and seasons, not on.

3. Confusing ‘At’ with ‘On’ for Days of the Week

Sometimes, learners mistakenly use at when referring to a day of the week. However, on is the correct preposition to use in these cases.

Common Mistake:

• Incorrect: We will leave at Monday.

• Correct: We will leave on Monday.

Explanation:

When talking about a specific day, always use on.

4. Using ‘In’ with Exact Times

Another frequent mistake is using in when referring to an exact time. As discussed earlier, at is the correct preposition for exact times.

Common Mistake:

• Incorrect: The meeting will start in 9 AM.

• Correct: The meeting will start at 9 AM.

Explanation:

At is used for specific times, while in refers to longer periods.

Expressions with Prepositions of Time

In addition to the basic uses of at, on, and in, there are many common expressions that incorporate these prepositions. Understanding these phrases will help you sound more natural and fluent in your communication.

Expressions with At

• At the moment – She is busy at the moment.
  This expression refers to the current time, often used to explain present circumstances.

• At the same time – We arrived at the same time.
  Refers to two actions happening simultaneously.

• At this time – At this time, we didn’t know the news.
  Refers to a specific point or moment in the past.

• At sunset – The view is breathtaking at sunset.
  Indicates the time when the sun sets.

• At night – I like to read at night.
  Refers to the time after sunset and before dawn.

Expressions with On

• On time – He was on time for the meeting.
  This expression means arriving or happening exactly as scheduled.

• On the dot – The show started on the dot at 7 PM.
  Refers to something happening exactly on the hour or at a precise time.

• On your birthday – I’ll give you a surprise on your birthday.
  Refers to an event happening on a specific day.

• On the weekend – I love to relax on the weekend.
  Refers to the time period commonly associated with Saturday and Sunday.

Expressions with In

• In the morning/afternoon/evening – We’ll meet in the afternoon.
  Refers to a general part of the day.

• In the past/future – In the past, I traveled a lot.
  Refers to a general time span before or after the present moment.

• In a minute/hour/day – I’ll be ready in an hour.
  Refers to a duration of time from the present moment.

• In the Middle Ages – In the Middle Ages, people lived very differently.
  Refers to a broader historical period.

Frequently Asked Questions about Prepositions of Time

To wrap up this article, let’s go through some frequently asked questions about at, on, and in to help clarify any remaining doubts.

Q1: What is a preposition of time?

A preposition of time is used to indicate when something happens. These prepositions give context to a sentence by telling us the time frame in which an event or action occurs. The most common prepositions of time are at, on, and in.

Q2: Which preposition do I use for a specific day?

When referring to a particular day, you should use the preposition on. For example:

• We are meeting on Friday.

• She was born on March 3rd.

Q3: Can I use at for months?

No, at is used for specific points in time, such as hours or moments of the day. For months, you should use in. For example:

• I will visit you in July.

• He was born in 1995.

Q4: Is it correct to say “on in the morning”?

No, on is not used with times of the day. When referring to parts of the day, you should use in. For example:

• I prefer working in the morning.

• We usually go for a walk in the evening.

Q5: What about using at with a month or season?

At is not used for months or seasons. Use in instead. For example:

• I’m planning to travel in the summer.

• We got married in December.