Preposition of Time

Using "at," "on," and "in"

We use at, on, and in to talk about time.

AT (for specific times)

We use at when we talk about:

✅ Clock times

• I wake up at 6:30 every morning.
• The train leaves sharp at 10. 

✅ Short, specific times of the day [dawn, dusk, noon & night]

• Let's meet at noon for lunch.
• It's quiet at night.
• She wakes up at dawn. 
• Cattle return home at dusk. 

✅ Festive times

• We're visiting our family at Christmas. [but on Christmas day]
• They'll be in Australia at Easter. 

✅ We say

• at the moment: I can't talk right now. I'm busy at the moment.
• at the weekend: Are you free at the weekend?
• at the end of: She came here at the end of December.

ON (for days and dates)

We use on when we talk about:

✅ Days

• We have a meeting on Thursday.
• I usually relax on Sundays.

✅ Time of a day when the name of the day is mentioned:

• I'm meeting Lisa on Wednesday afternoon.
• He'll come on Sunday morning. 
• What are you doing on Friday evening?
• I'll be free on Monday night. 

✅ Special days

• The party is on 10th August.
• We celebrated on New Year's Eve.

IN (for months, years, and longer periods)

We use in when we talk about:

✅ Months

• We're moving house in July.

✅ Years

• I was born in 2006.

✅ Parts of the day when the name of the day is not mentioned:

• I'm meeting Lisa on Wednesday afternoon. [but: in the afternoon]
• He'll come on Sunday morning. [but: in the morning]
• What are you doing on Friday evening? [but: in the  evening]
• I'll be free on Monday night. [but: in the night]

✅ Seasons

• Birds sing beautifully in the spring.

✅ Centuries

• Important changes happened in the 20th century.

Important Notes

We say:

• in the morning / in the afternoon / in the evening

➔ Example: I drink coffee in the morning.

BUT when we include the day:

• on Monday morning / on Friday evening / on Saturday night

➔ Example: We are meeting on Tuesday afternoon.

No AT/ON/IN before these words:

❌ Don't use at, on, or in with:

• this (this morning, this year)
• last (last week, last December)
• next (next Friday, next month)
• every (every day, every winter)

Examples:

• We're visiting grandma this afternoon. (✅)
• I travelled to Italy last summer. (✅)
• She's starting a new job next Monday. (✅)
• We go camping every summer. (✅)
• (NOT "on next Monday" or "in last summer" ❌)

IN + Time from Now

In is also used to talk about something that will happen after a period of time from now.

👉 Examples:

• The bus arrives in ten minutes. [Meaning: Ten minutes from now.]
• We'll see you in a week. [Meaning: A week from now.]
• I’m starting a new course in three months. [Meaning: Three months from now.]

"At," "on," and "in" at a glance:

Using "from ... to" & "until"

We also use from......to, until, since and for to talk about time.

From ... To / From ... Until

We use from ... to or from ... until to show the starting point and the ending point of something.

👉 Examples:

• We lived in Brazil from 2015 to 2021.
• I work from Tuesday to Saturday.
• They studied from 9 a.m. until 5 p.m.

You can use until instead of to:

• The museum is open from April until September.

• We lived in Brazil from 2015 until 2021.

Until / Till

We use until (or till) to say that something continues up to a certain time.

👉 Examples:

• They're staying at the beach until Sunday.
• I read stories until midnight last night.
• We'll be busy until next month.

Till means the same as until (informal):

• They're staying at the beach till Sunday.
• I read stories till midnight last night.
• We'll be busy till next month.

Compare

Using "since" and "for"

We use for and since to talk about how long something has been happening.

Since

We often use since with the present perfect tense (have/has been, have/has done, etc.).

👉 Examples:

• Mia has been in the hospital since Thursday.
• Tom and Laura have been friends since 2010.

We use since when we talk about the starting point of something (like Monday, 2010, or 5 PM).

👉 Examples of starting points:

• since Monday
• since 5 o'clock
• since April
• since 2015
• since Christmas

Examples:

• Daniel has been in Spain since April.
• We've known each other since 2014.
• I have studied English since January.

Think:

since = from a point in the past to now

Compare "from ... to" and "since"

• We lived in Brazil from 2015 to 2021. (specific period, finished)
• Now we live in Portugal. We moved in 2021. We have lived in Portugal since 2021. (still true now)

For 

We use for with a period of time — how long something happens.

👉 Examples:

• Mia has been in the hospital for four days. (✅ not "since four days")
• They've known each other for fifteen years.
• I stayed in Paris for a month.
• We're going away for the weekend.

We use for when we talk about a length of time (like two hours, five days, or three years).

👉 Examples of time periods:

• for two hours
• for five days
• for three months
• for ten years
• for a long time

Examples:

• Daniel has been in Spain for three weeks.
• We've known each other for ten years.
• I have studied English for six months.

🛑 Not: "since three weeks" or "since ten years" — use for with a length of time!

Think:

• for → how long (a period)
• since → when it started (a point in time)

Quick Table

Practice Exercise: From ... To / Until / Since / For

Complete the sentences with from ... to, until, since, or for:

1. I lived in New York __________ 2010 __________ 2018.
2. Please wait here __________ I come back.
3. We have been best friends __________ we were five years old.
4. Sarah has been sick __________ three days.
5. The library is open __________ 9 a.m. __________ 5 p.m.
6. I haven't eaten anything __________ yesterday.
7. I'm staying in London __________ two weeks.
8. They studied at the university __________ 2015 __________ 2019.
9. The rain continued __________ midnight.
10. He has worked at the bank __________ ten years.

Using "ago"

Using "ago"

Ago means before now.

It tells us how much time has passed since something happened.

We use ago with the past tense (started, left, was, went, etc.).

Examples:

• Mia moved to Canada six months ago. (= six months before now)
• "When did you see him?" "I saw him two days ago."
• We had lunch an hour ago.
• People traveled by horses a hundred years ago.

Compare "for," "since," and "ago"

🛑 Be careful!

1. For is used for how long something continues.
2. Since is used for when something started.
3. Ago is used to say when something happened in the past.

👉 Example 1:

When did Daniel arrive in Spain?

— He arrived three weeks ago.

How long has he been in Spain?

— He has been in Spain for three weeks.

👉 Example 2:

When did you start learning guitar?

— I started learning two years ago.

How long have you been learning guitar?

Practice Exercise: For / Since / Ago

Fill in the blanks with for, since, or ago:

1. Julia has lived in Paris _______ 2021.
2. I finished my homework an hour _______.
3. We have been friends _______ ten years.
4. My brother bought a new car two months _______.
5. It has been raining _______ this morning.
6. I moved to this city five years _______.
7. He has been at the gym _______ two hours.
8. She has worked at the bank _______ she graduated.

Using Before, After, During, and While

We use before, during, and after to talk about time.

Before, During, and After (with nouns)

👉 Examples:

• I always feel excited before a holiday.
• It started raining during the match.
• We went out for dinner after the meeting.

Before, While, and After (with verbs)

We use before, while, and after when talking about actions (verbs).

👉 Examples:

• Remember to lock the door before you leave.
• I like listening to music while I'm studying.
• They watched TV after they finished their homework.

During vs. While vs. For

During is used with a noun (during the party).

While is used with a subject and verb (while I was dancing).

👉 Examples:

• We stayed quiet during the movie. (noun)
• We stayed quiet while the movie was playing. (subject + verb)

✅ Correct:

• I slept during the flight.
• I slept while we were flying.

❌ Wrong:

• I slept during we were flying. (❌)

We use for (not during) to talk about a period of time (three days, two hours, etc.).

👉 Examples:

• I studied for three hours. (not "during three hours")
• We lived in Spain for six months. (not "during six months")

Before/After + -ing

We can use before and after with an -ing verb (verb+ing).

👉 Examples:

• I always wash my hands before eating dinner. (✅ not "before to eat")
• After finishing his homework, Leo went out to play. (✅ not "after to finish")
• She read a book before going to bed.
• After cleaning the kitchen, we relaxed.

✅ Say: before eating, after cleaning

❌ Not: before to eat, after to clean

Quick Chart

Practice Exercise: Before / After / During / While / For

Complete the sentences with: before, after, during, while, or for.

• I always brush my teeth __________ going to bed.
• We heard a strange noise __________ the concert.
• Please turn off the lights __________ you leave the room.
• She fell asleep __________ she was watching TV.
• I stayed in Italy __________ two weeks last summer.
• We went out for ice cream __________ the movie ended.
• Be quiet __________ the baby is sleeping.
• He got very nervous __________ the interview.
• After __________ dinner, they went for a walk.
• They lived in Australia __________ three years.