1. I have to wake up tomorrow at 6:00. clock
 2. He’s at work today.
worker
 3. They’re at church right now.
at church

 4. John decided to stay at home today because he’s sick.

house
5. She’s studying at the library. at the library

 6. My favorite radio station is at 91.1 FM on the radio dial.

radio
 7. She was at school yesterday.
school
 8. They’re at the park.
at the park

 9. Andrea lives at 2124 Oak Street.

 Right now she’s at home.

(Use “at” for an address.)

house

Use the preposition “at” for time and place.