at campus与on campus有什么不同

at and on is similar
depending on the object
but for example ,you can say I am on home,it should be I am at home.
you can also say I am at the bus now .I am on the bus now.I am in the bus now.
as far as I know
at = a place where you are
on = a place where u are,your position,your situation
About at campus / on campus.
for example ：Mary is at her campus having her maths class now.
Mary in on campus having her class now
Normally you do not add sb's between on and campus,but you can add sb's between at and her campus.cos the campus is a place that belongs to everyone