What you'll learn
By the end of this lesson, you'll be able to say when things happen using in, on, and at with the right time group every time.
When do I use it?
You use time prepositions to connect an event to a moment on the clock or calendar: "I wake up at seven," "We play on Fridays," "She was born in 1990." The rule is simple: the size of the time controls the preposition — big windows take in, single days take on, and exact moments take at.
How do I form it?
at => exact times, night on => days and dates in => months, years, seasons, and parts of the day
- at 5 pm, at noon, at night
- on Monday, on the 12th of May, on my birthday
- in March, in 2026, in winter, in the morning
No preposition at all is needed before today, tomorrow, yesterday, this, next, or last: say "tomorrow morning", "next week", "last month" — never "in tomorrow" or "on next week".
Common mistakes for Spanish speakers
"En" is the only word Spanish needs ("en lunes", "en la mañana", "en las 5"), but English splits it across in, on, and at by the size of the time. Do not translate "en" directly; instead place the time in its group: a day (Monday) goes with on, an hour (5 o'clock) goes with at, a month or a year goes with in. Also, Spanish adds "en" to "today, tomorrow" ("en mañana") but English uses those words with no preposition: "mañana" is "tomorrow", not "in tomorrow".
Clap the size of the time: an exact tick (at), a whole day or date (on), a long window like a month or year (in).
Practice
Multiple Choice
A1Which sentence is correct?
Fill in the Blank
A1The train leaves 6:30 in the morning.
Hint: Exact times take 'at'.
Find the Error
A1Sentence Transformation
A1Task: Say when you visit her, using the right prepositions
Hint: A named day keeps 'on'; the day name and part of day can combine as 'on Sunday morning'.
Practice Speaking
Apply what you've learned in a real conversation with AI feedback.
Level: A1