CARROTTA
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⏰ Compendium
Grammar
EN
English — Prepositions of time
English uses at, on and in to place events in time, plus a set of duration and boundary words like for, since, by and until. The choice depends on how precise the time reference is: at 7 o'clock, on Monday, in July.
1
How it works
✓ Rule
Use at for clock times and festivals (at 6 pm, at Christmas), on for days and dates (on Monday, on 5 May), and in for longer periods — months, seasons, years and parts of the day (in July, in 2025, in the morning).
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Examples
| Preposition | Typical use | Example |
|---|---|---|
| at | clock times, festivals, night | at 7 o'clock, at Easter, at night |
| on | days and dates | on Friday, on 5 May, on my birthday |
| in | months, years, seasons, parts of the day | in April, in 2025, in the evening |
| for | length of a period | for two hours, for a week |
| since | starting point up to now | since Monday, since 2020 |
| until / till | up to an end point | until Friday, till midnight |
| by | not later than a deadline | by 6 pm, by next week |
| from ... to | start and end of a span | from 9 to 5, from Monday to Friday |
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Good to know
⚠ Note
Drop the preposition before this, last, next, every and tomorrow: say see you next week and I'll call you tomorrow, not on next week. Also note at night but in the morning / in the afternoon / in the evening, and for + a length of time vs since + a starting point: I've lived here for five years / since 2020.