at school
At one's school.
Melanie can't come on Monday, because she will be at school.
I left my history book at school.
A child educated only at school is an uneducated child. George Santayana
When I get into trouble at school I'd like to take an invisibility cloak, drape it over me and sneak out the door. Or I'd like to have a 3-headed-dog because then no one would argue with me. Daniel Radcliffe
The most important thing we learn at school is the fact that the most important things can't be learned at school. Haruki Murakami
I spent all my time at school in the library. Bad teachers can teach you to learn on your own. Gregory Colbert
Six hours a day I lived under school discipline in active intercourse with people none of whom were known to those at home, and the other hours of the twenty-four I spent at home, or with relatives of the people at home, none of whom were known to anybody at school. Georg Brandes
A foreign language is more easily learned in the kitchen than at school. German Proverb