The prepositions in, on, and at can be used to indicate time and place. Notice how they are used in the following situations:
In 1999, In December
|Country, State, City|
In Japan, In Utah, In Taipei
On Saturday, On May 1
On Main Street, On 1st Ave.
At 8:00, At 7:30
At 815 East Main Street
A: Where's your office?
B: In Jakarta, Indonesia.
A: Really? What part of jakarta?
B: It's on Pegangsaan Timur Road.
A: I know that area. Where exactly is it?
B: It's at Pegangsaan Timur Road no.12 , next to the bookstore.
C: When is the wedding?
D: It's in June.
C: What day?
D: It's on Saturday, the 25th.
C: What time?
D: It starts at 6:00.
When talking about locations, use at to indicate the general vicinity or area, and in to
indicate inside the building, enclosed area, etc. For example:
at the swimming pool (on site)
in the swimming pool (in the
at the post office/bank (general)
in the post office/bank (inside the building)
at the zoo (visitors, general area)
in the zoo (animals in their cages)
in the classroom
I met my wife at the theater. (while watching a movie)
I spilled my drink in the theater (on the floor of the building)
She works at the library on Wednesdays.
She found a rare coin in the library (building).
Dr. Jones works at the hospital every day.
John was in the hospital for a week with a broken leg.
For school, prison, and church, the is used to indicate the building. No article indicates
the general situation. Note the following:
in school (studying, listening to teacher, etc.)
in the school (building)
in jail/prison (staying there as a criminal)
in the jail/prison (temporary)
in church (praying, listening to a sermon, etc.)
in the church (building)
in church (attending services)
in the church (fixing the windows)
at the church
in prison (He committed a crime.)
at the prison (visiting his friend)