Particle - で - Place - at, in, on (place)
で is a particle used to say where an action is happening: 猫は家で眠ります (The cat sleeps at home).
Note that this particle cannot be used in combination with ある (to exists) or いる (to be alive), except when talking about an event which happens over a period of time like a party or meeting.
See you tomorrow at school.
I want to buy a hat in Kyoto
Cows are eating grass in the meadow
Let's eat chicken in hiroshima at four
Please put your seal here
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This is the most embarrassing moment of my life