1. I promise to meet her at school.
2. I promise to meet her in school.
Are the above writing correct? If both are correct, then what are the differences between them?
Ju
I think the first is more common. 'At school' to me is purely geographical, while 'in school' is more conceptual -- during lessons, among classes, while studying.
Examples:
I met my wife in university, though most of my friends met theirs in high school.
I got lost on Saturday at school, so I must have a bad sense of direction.