1. We use at for exact points of time.
Example: at midday, at noon, at midnight, at 5 o’clock, at 8:15.
2. We use at with other short periods of time that we think of as points of time.
Example: at the end of March, at the beginning of the year.
- We get our salary at the end of the month.
3. With mealtimes such as breakfast, lunch, dinner, etc.
- Today at breakfast he said that he was leaving to Australia.
- We will discuss it at dinner tonight.
4. We use at with night when we mean ‘when it is night’ or ‘each night’.
- In the islands, it is dark at night because street lights often don’t work.
5. We use at in the phrase ‘at the moment’ to mean ‘now’.
- He is not in the office at the moment.
6. We use at with short holidays periods such as weekends, Eid holidays, Christmas, Easter, etc.
- We will meet up at the weekend.
1. We use in when we talk about longer periods of time such as seasons, months, years, decades, centuries, etc.
- In the summer, the skies are clear and we can go for picnic.
- In the days that we lived in that house, we used to make barbecue every Friday.
2. We use in when we talk about how long it will be before something happens.
- We will reach our island in an hour’s time.
3. We use in to say how long something takes.
- He finished his work in a few weeks.
4. We use in with parts of the day such as the morning, the evening, etc.
- Haisham takes his lunch usually at 2 o’clock in the afternoon.
We use on when we talk about a particular day, date or part of a particular day.
- let us hold a meeting on Saturday.
- It’s my birthday on the 17th.
Note: We rarely use at, in, or on before the words all, any, each, every, last, next, one, this, or that when these words are followed by a time expression.
Example: I’ve been trying to call you all morning (not …in all morning).