منتديات مدينة الاحلام - When can I use 'in', 'on' and 'at'?

Prepositions: In, On, and At (with specific times and places)
The prepositions in, on, and at can be used to indicate time and place. Notice how they are used in the following situations:
Preposition
Time
Place
In

Year, Month, In 1999, In December

Country, State, City In Japan, In Utah, InTaipei
On

Day, Date On Saturday, On May 1

Street On Main Street, On 1st Ave.
At

Time At 8:00, At 7:30

Address At 815 East Main Street
In many languages, there is only one preposition for the above situations. In English there are three. Just remember that in usually indicates the "largest" time or place, and at usually indicates the "smallest" time or place.
Examples:
A: Where's your office?
B: In Taipei, Taiwan.
A: Really? What part of Taipei?
B: It's on Chung Shan North Road.
A: I know that area. Where exactly is it?
B: It's at 105 Chung Shan North Road, 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.

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