In On At

In On At

Time and Place

Prepositions of Time

We use:

• "At" for a PRECISE TIME

• "In" for MONTHS, YEARS, CENTURIES and LONG PERIODS

• "On" for DAYS and DATES

"At"

PRECISE TIME

• at 3 o'clock

• at noon

• at bedtime

"At"

PRECISE TIME

• at sunrise

• at the moment

"In"

MONTHS, YEARS, CENTURIES and LONG PERIODS

• in May

• in summer

• in 1990

"In"

MONTHS, YEARS, CENTURIES and LONG PERIODS

• in the next century

• in the Ice Age

• in the past/future

"On"

DAYS and DATES

• on Sundayon

• on Tuesdays

• on 6 March

• on Christmas Day

"On"

DAYS and DATES

• on Independence Day

• on my birthday

• on New Year's Eve

Examples:

• I have a meeting at 9am.

• Jane went home at lunchtime.

• In England, it often snows in December.

• Do you think we will go to Jupiter in the future?

Examples

• There should be a lot of progress in the next century.

• Do you work on Mondays?

• Her birthday is on November 20th

When we say last, next, every, this we do not also use at, in, on.

Examples

• I went to London last June. (not in last June)

• He's coming back next Tuesday. (not on next Tuesday)

• I go home every Easter. (not at every Easter)

• We'll call you this evening. (not in this evening)

Prepositions of Place. We use:

• At:  tells us that the following noun is located at a specific point or location. It shows an exact position.

• In: tells us the noun is in an enclosed space (surround or closed off on all sides). Basically, when something is inside something.

• On: tells us that the following noun is located on a surface. Use on when one thing is attatched to or touching somthing.

At a Point

• "She's waiting at the entrance."

• "He's sitting on his chair at his desk."

• "I work at a bank."

In an Enclosed Space

• In a box.

• In a room.

• In a country.

On a Surface

• On the table.

• On the floor.

• On the chair.

What's the difference bewteen these two sentences?

She's at the library.

She's in the library.

She's at the library.

The emphasis is on the her location and the type of place she has gone to.

She's in the library. - the emphasis is on the type of building she is in.