I'd like to ask about using 'at' and 'in' in sentences such as the following:
At the University he studied French and Italian as well.
Can 'in' be used in place of 'at' or only 'at' is correct. I think I've seen sentences like "In college I studied..." written by native English speakers.
You are welcome. Your sentence would be better rewritten as below.
At University he studied French(,) and (also) Italian. Without 'also' you don't need the comma.