Daily Quiz: Prepositions of Time (Beginner)

in, on, at — this time for telling the time

You’ve probably met “in”, “on” and “at” for places — in a city, on a table, at the airport. Here’s the neat part: the very same three words handle time as well, and they follow a pattern that’s just as tidy once you see it. Learners often feel these are random and try to memorise every example separately, but you really don’t have to. There’s a size logic, exactly like with places.

Picture time as a set of containers, from big to small. “In” is for the big blocks — long stretches of time that wrap around you: months, years, seasons, and parts of the day. In June, in 2020, in winter, in the morning. “On” is for specific days and dates — a single square on the calendar: on Monday, on my birthday, on 5 June, on New Year’s Day. And “at” is for exact points on the clock, the smallest, most precise moments: at 5 PM, at noon, at midnight, at the moment. So the pattern runs big to small — in (long periods), on (single days), at (clock times) — mirroring the place rule where “in” is the biggest and “at” is the pinpoint.

Then there’s a second little family of time words that this quiz also tests: “by”, “for”, and “since”. These aren’t about “when” so much as about deadlines and durations, and they trip people up in their own way. “By” marks a deadline — the latest something can happen. “For” measures how long something lasts. “Since” marks the starting point from which something has continued. I’ll untangle those clearly as we go, because “for” versus “since” in particular is one of the most common mix-ups I see. Let’s run through the five questions and let the size logic — plus those deadline words — do the heavy lifting.

The answers, explained

1. “I have a meeting ___ 5 PM.” — the answer is “at.” “5 PM” is an exact time on the clock — the smallest, most precise kind of time — so it takes “at”. This is the core use of “at” for time: at 5 PM, at 9 o’clock, at noon, at midnight. The traps “in” and “on” are for bigger blocks and for days, not for clock times. Whenever you can point to a specific hour and minute, “at” is your word.

2. “My birthday is ___ June.” — the answer is “in.” “June” is a whole month — a big block of time — and months take “in”. The same goes for years (in 2020), seasons (in summer), and parts of the day (in the morning, in the evening). The trap “on” would only be right if we named a specific date, like “on 5 June”. But bare “June” is the whole month, so it’s “in June”. Big stretch of time equals “in”.

3. “She was born ___ Monday.” — the answer is “on.” A day of the week is a single square on the calendar, and single days take “on”: on Monday, on Friday, on my birthday, on 12 March. The trap “in” is for longer periods, and “at” is for clock times — neither fits a named day. If you can point to one particular day or date, “on” is correct. (One quirky exception to file away for later: we say “at the weekend” in British English, though Americans say “on the weekend”.)

4. “We’ll finish the project ___ the end of this month.” — the answer is “by.” Here we’ve left the in/on/at family and moved to deadlines. “By” means “no later than” — it marks the latest point by which something must happen. “We’ll finish by the end of the month” means the finish will come at or before that moment. The trap “at” would just mark a point in time without the sense of a deadline, and “in” would mean a period. When you’re talking about a cut-off — the last acceptable moment — “by” is the word: finish by Friday, reply by 5 PM.

5. “I’ve been studying English ___ 2020.” — the answer is “since.” “2020” is a specific starting point, and when you name the point where an ongoing action began, you use “since”: since 2020, since Monday, since I was a child. The strong trap here is “for”. “For” measures a length of time — for two years, for six months — a duration, not a starting point. So it’s “since 2020” (the start) but “for four years” (the length). A handy test: if the word after the gap is a point in time, use “since”; if it’s a stretch of time, use “for”. And notice the sentence uses “I’ve been studying” — the present perfect — which pairs naturally with both “since” and “for”.

Quick rules to remember

Start with the size logic for in/on/at. “In” = long periods: in June, in 2020, in winter, in the morning. “On” = single days and dates: on Monday, on my birthday, on 5 June. “At” = exact clock times: at 5 PM, at noon, at midnight. Big to small, just like with places. Then the deadline-and-duration words: “by” = a deadline, the latest something can happen (finish by Friday). “since” = a starting point (since 2020). “for” = a length of time (for two years). The two mistakes I correct most are mixing up “since” and “for” — remember, point in time versus stretch of time — and reaching for “at” with months when it should be “in”. Get the size right and most of your time prepositions will fall into place.