A question about prep.
Hello, everyone.
"Tony worked in a lawyer`s office years ago, but he is now working at a bank.", in this sente, why does use "in" and "at" ? Can i change it?
Thank you.

Because:
1. You work IN an office.
2. You work AT a place.

Those are the rules. Learn them.

It's very common for people to use "at" instead of "in" in sentences like that, so the meaning of the sentence is still understood.