Time prepositions are words at the beginning of phrases which tell us when something happens or for how long.
Use of IN
We use In with periods of time:
1. Parts of the day : early in the morning, in the afternoon, in the evening.
2. Months : in September, in October......
3. Seasons : in (the) summer, in (the) autumn, in (the) winter ............
4. Years : in 1971, in 2011 ........
5. Decades and centuries : in the 1930s, in the 21th century.....
6. In can mean 'during or within a period of time'
He is expected to land in 24 hrs.
7. In can also mean 'at the end of a period of time'
Wait down there.......I am coming in 5 minutes.
8. There are some idiomatic expressions using in :
In time = (a moment before it is too late)
I made the meeting last night in time.
In plenty of time for = (a long time before something)
Sonia got to the cinema in plenty of time for the film.
Use of On
We use On with time expressions to say that something happens during a particular day or date:
1. Days : on Monday, on Sunday, on his birthday, on Christmas day.......
2. Dates : on October the 4th, on November 3rd..........
3. With parts of days/dates : On Friday afternoon, on Sunday morning.......
4. Phrasal use : on time =( at exactly the right time)
I am on time today...right?
Use of At
1. We use at in expressions which mean something happens exactly at a particular time.
The shop closes at half-past five.
2. We also use at to talk about something that happens during the night or the weekend:
It gets very cold at night in the desert.
We always go to the beach at the weekend
{Note: In US English people say on the weekend.}
3. There are some idiomatic expressions which use at such as:
At the moment = during the period of time.
Kanta is studying electronic engineering at the moment at BUET.
Use of BEFORE, AFTER, and DURING
1. We use BEFORE and AFTER to talk about a sequence of events, and we use AFTER with periods of time:
Sadi had to get home BEFORE midnight.
AFTER a couple of months Pavel got a job as a translator.
2. We use DURING for something that continued through a specific period of time.
DURING 1998 Fahim was working in Thailand.
2. We use DURING for something that continued through a specific period of time.
DURING 1998 Fahim was working in Thailand.
3. We also use DURING when we are talking about something happening within a period of time:
We ate popcorn DURING the film.
