At university or at a university?

Question
Which one is correct, "at university" or "at a university"?


Answer
Speakers of British English use “at university.” Speakers of American English use “at a university.”  However, these two phrases do not have exactly the same usage. “At university” (British) means “attending college or graduate school,” as in:

• Charles and Sara met while they were at university.

“At a university” (American) often has a more literal meaning that indicates the location of someone or something, as in:

• I work in a lab at a university.

To describe someone who is attending college or graduate school, most Americans would say “in college,” or “in graduate school.” The preposition in is also used for other kinds of school, as shown in the examples below.

• My best friend Susannah is in college on a full scholarship.
• When Ward was in graduate school, he worked at a law firm during the day and attended classes at night.
• Many students in American high schools speak a language other than English at home.