Is it “in July” or “on July”? Can I say “at 8 p.m.” or “on 8 p.m.”?
See you “in Sunday” or “on Sunday”? If those are your questions, I’m here to answer!
This is a guide for you who’s struggling on using prepositions of time.
Is it “in”, “at”, or “on” ? Learn how to know which preposition to use from this easy guide.
What are prepositions of time?
Prepositions of time are words that show us the time relationship between actions or events.
They are often used to talk about schedules and routines. Moreover, they give information about when things happen and how long they last.
The most common prepositions of time are “in,” “on,” and “at.” The others are : by, until, before, after, during and for. Let’s see some examples of them.
1. In
“In” has a similar meaning as “during”. Use “in” before :
- months, years, seasons, centuries
Examples :
I was born in 1994.
We’re going to Mexico in January.
My mother loves making soup in (the) winter.
It’s too hot here in summer.
I think life was hard in the 1800s. (pronounced “eighteen-hundreds”)
- general times of day : morning, afternoon, evening
Examples :
She goes to the gym in the morning.
The canteen is always full in the afternoon.
She’ll be here in the evening.
Note :
You can say “in the night” or “at night” depending on the context.
“In the night” usually refers to one particular night and is commonly used in writings such as stories or poems; “at night” refers to any night in general. For daily use, just stick to to “at night”.
For example:
She was awake in the night, thinking about the journey ahead.
It’s not safe for ladies to travel at night.
- a period of time
Examples :
This book tells a story in the Middle Ages.
In the twenty-first century, education has evolved significantly.
We cannot live without technology in the 21st century. (pronounced : “twenty-first”)
- expressions of time
Examples :
That story was in the past. You have to move on.
In the future, the robots will take away our jobs.
She has been working hard in the last few years/months/weeks/days.
- to show how soon something happens
Examples :
I’ll meet you in 15 minutes.
The rice will be ready in five minutes.
2. At
Use “at” :
- to express the exact time of the day when something happens
Examples :
I always come home at 7 p.m.
She has an appointment at 8 o’clock in the morning.
We have a meeting at lunchtime.
We’ll meet them at dinnertime.
We usually take our lunch break at noon.
She practices yoga at sunrise every morning.
That old man always sits on his porch at sunset.
- for a point of time
Examples :
Everything was fine at the beginning of the concert.
At the end of the day, we’ll get the exam results.
(At the end of the day can be an idiom. Meaning after everything is considered. You use it before giving the most important fact of a situation. Check the example here on Cambridge Dictionary.)
- for seasonal holidays
Examples :
We will stay in Florida at Christmas.
(Christmas here refers to multiple days during the Christmas holiday)
At Easter, we will paint a lot of eggs.
- for time expressions
Examples :
I stay at home at the weekend. (British English)
She’s not here at weekends. (British English)
(We add an “s” to “weekend” to refer to every weekend.)
At first, I didn’t understand the theory.
He found the missing key at last.
At present, we are working on a new project.
I am studying for my exams at the moment.
At times, the weather in this region can be quite unpredictable.
(“At times” has a similar meaning with “sometimes”. “At times” is more formal.)
I need that report on my desk at once.
(“At once” has a similar meaning with “immediately”. “At once” is more formal.)
3. On
Use “on” :
- for days of the week when something happens
Examples :
She works on Mondays.
(We add an “-s” to “Monday” to show that this occurs regularly. It means she works every Monday.
In American English, we can omit the preposition and say “ She works Mondays.”)
We’ll visit my aunt on Sunday morning.
She’ll leave for work on Monday.
I stay at home on the weekend. (American English)
- for dates
Example :
Halloween is celebrated on October 31. (American English)
(Pronounced: “October thirty-first.” We don’t specify the year because Halloween occurs on the same date every year.)
The conference starts on the 15th of June. (British English)
(Pronounced: “the fifteenth of June.” You don’t need to include the year if the conference is happening in the current year.)
She was born on September 6, 2010.
- To refer to a special day, an exact day or fixed date
Examples :
She will arrive on Christmas.
(It means she will arrive on 25th December, the date when Christmas is celebrated on the calendar.)
They plan to exchange gifts on New Year’s Eve.
(It refers to the night of December 31st.)
She proposed to her boyfriend on his birthday.
4. By and until
“By” and “until” are commonly used to indicate deadlines or limits.
Use “by” to indicate something that happens not later than or probably before the time mentioned.
Examples :
He plans to arrive in California by the end of June.
(He will probably arrive before 30th June or on 30th June.)
We will finish building this fence by four o’clock.
(The fence will be done before four o’clock or at four o’clock, not later.)
“Until” means that something is in progress and keeps continuing until the time mentioned, not later than that.
Examples :
The museum will remain closed until this evening.
(It will open the next day.)
“Until” is often used with a negative, meaning “not before”.
We can’t start the party until my parents arrive.
(We can start it when they’re here.)
5. Before and after
Use “before” to show that something happens earlier or comes first in time compared to another thing.
Examples :
I’ll come home before 7 p.m.
(Maybe I’ll be home at 6.30 p.m.)
She’ll be home before dinner.
(She arrives first, then the dinner’s served.)
Use “after” to say something happens later than something else.
Examples :
We’ll be home after the show.
(The show ends, then we go home.)
She went to the grocery store after work.
(She finished her work then went to the grocery store.)
6. During and for
“During” indicates a specific time or period in which something happens or occurs. Sometimes it shows interruption.
Examples :
We often go camping during the summer.
The dogs are released during the night.
They left the seminar during the major’s speech.
(When the major was giving a speech, they left.)
Use “for” as a preposition of time to show how long something lasts or continues.
Examples :
He will stay at the hotel for two days.
She has been living here for five years.
We went to Florida for the summer.
Important note in using prepositions of time
You can skip “at”, “in”, “on” as prepositions of time when you see last, next, every, and this before the time.
For example :
- We visited my grandmother in last June. (wrong)
We visited my grandmother last June. (correct) - He’s coming back on next Tuesday. (wrong)
He’s coming back next Tuesday. (correct) - I go home at every Easter. (wrong)
I go home every Easter. (correct) - We’ll call you in this evening. (wrong)
We’ll call you this evening. (correct)
Conclusion
Prepositions of time “in”, “at”, and “on” are commonly confused with each other.
To make it easier to remember, keep these in mind :
- at for a precise time
- in for months, years, centuries and long periods
- on for days and dates
Try doing some ‘in, at, on’ exercises for prepositions of time on the British Council’s website.
Or, make your own mnemonic device to remember them
In 2000, Sally went to the dentist at 8 o’clock on Sunday.
Sometimes you’ll see ‘in,’ ‘at,’ and ‘on’ used not to indicate time, but to describe locations or places.
Go to my post Prepositions of Place to learn more about them.
Grammar book reference
Azar, Betty Schrampfer, et al. Basic English Grammar. Pearson Education, 2014.
DK. English for Everyone: English Grammar Guide: A Comprehensive Visual Reference. DK Publishing (Dorling Kindersley), 2016.
Thomas, Barbara, et al. Grammar and Vocabulary for First and First for Schools Book with Answers and Audio. Cambridge University Press, 2015.
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