This post starts with the most common use of the three prepositions, followed by other usages. Wherever possible, the prepositions have been presented in tabular form for ease of comprehension. Comments are in square brackets in blue font so that you can easily spot them. And the post ends in a quiz for you to test yourself.
Let’s start with the most common use of the three prepositions.
1. The most common use of At, On, and In
|It is used with exact point of time.||It is used for a particular day, date, or part of the day.||It is used for longer periods such as months, seasons, years, decades, and centuries.|
|At 4 PM [Exact time]||On Thursday [Particular day]||In 1986 [A long period]|
|At 3 o’clock||On Thursday morning [Part of the day]||In the 20th century|
|At sunrise/ sunset||On Christmas/ Independence Day [Particular day]||In 1970s|
|At midnight||On 06 April 2016||In April|
|At noon||On his birthday||In summer|
2. Other use of At
With short holiday periods:
With other short periods that are treated as points:
With night when we mean ‘when it is night’ or ‘each night’:
3. Other use of On
We say on time to convey that someone or something is not late:
We say on the dot to convey that something happened at the exact time specified:
4. Other use of In
With parts of the day:
When we talk about how long it will be before something happens:
When we say how long something takes:
We don’t use at, on, or in before all/ any/ each/ every/ last/ next/ one/ some/ this/ that/ today/ tomorrow/ day after tomorrow/ soon/ later:
Fill in the blanks with the preposition of time at, on, or in.
1. Many medical treatments with no scientific basis originated ___ the middle ages.
2. Polar bears hibernate ___ winter.
3. X: What are planning ___ Easter Day? Y: Nothing much. Though I may go out of the town for two days.
4. I’ll see you ___ noon in your office.
5. I got more presents than I expected ___ my birthday.
6. Some of the best music was composed ___ 1980s.
7. Will you be in the town ___ Christmas?
8. I’m planning a trip to my hometown ___ the end of April.
9. Can we meet ___ Monday evening?
10. Can we meet ___ the evening today?
1. in 2. in/ during 3. on 4. at 5. on 6. in 7. at 8. at 9. on 10. in