Prepositions of Time

Prepositions of Time

Small words like at, on and in tell us when something happens. We put them before the time word.

Structure

• Pattern: subject + verb + at/on/in + time word. Example: We meet at ten.
• at: clock times and some fixed phrases, such as at night and at the weekend. Example: The class starts at nine. (In American English: on the weekend.)
• on: days and dates. Example: I work on Monday.
• in: months, years, seasons and parts of the day. Example: We travel in June.

How the Grammar Works

1. Say what happens. Example: I meet Tom.
2. Is it a clock time? Use at. Example: I meet Tom at 5 PM.
3. Is it a day or a date? Use on. Example: Her birthday is on Friday. The party is on July 4th.
4. Is it a month, a year, a season or a part of the day? Use in. Example: in April, in 2023, in summer, in the morning, in the afternoon, in the evening.
5. Remember: we say at night, not in the night. Example: I work at night.
6. Do not use at, on or in with this, next, last, every, today, tomorrow and yesterday. Example: We meet next Monday.

Common Use Cases

• Daily routine: I get up at 7 o'clock. I study in the evening.
• Schedules: The shop opens at noon. The shop is closed on Sunday.
• Birthdays and special days: My birthday is on May 5th.
• A part of one day: we use on with a day + part of the day. We say in the morning, but on Monday morning. Example: I have class on Monday morning.
• No word before these time words: this morning, last week, every Friday, tomorrow. Example: I see Ana tomorrow.

Frequent Mistakes and How to Avoid Them

• Incorrect: at Monday. Correct: on Monday. We use on with days.
• Incorrect: on April. Correct: in April. We use in with months.
• Incorrect: in 3 PM. Correct: at 3 PM. We use at with clock times.
• Incorrect: in the night. Correct: at night. This is a fixed phrase.
• Incorrect: on next Monday. Correct: next Monday. No word is needed before next.
• Incorrect: in this evening. Correct: this evening. No word is needed before this.
• Incorrect: in Monday morning. Correct: on Monday morning. A day + part of the day uses on.

Comparison with Related Grammar

• The words at, on and in also tell us where. Compare at ten (when) and at school (where).
• Compare on Monday (when) and on the table (where).
• Compare in June (when) and in the kitchen (where).

Example Sentences

• We meet at ten.
• My birthday is on December 10th.
• I work on Monday.
• She jogs in the evening.
• I sleep at night.
• We go to the beach in August.
• I have class on Monday morning.
• I see Ana tomorrow.

When to Use This Rule

Use at, on and in to say when something happens. Use no word with this, next, last, every, today, tomorrow and yesterday.