Thst is a badly phrased question. "What languages do you speak?", would be the question to ask.

Because even of you were thinking about spoken languages, what does "knowing" mean? I "know" Hungarian exists, I know how Hungarian sounds like, I know how Hungarian words look like, but that doesn't mean I speak or understand it. Now if it was clear they meant apoken languages we could infer from the context they want to know about our skills with different spoken languages and didn't read our CV, which at least where I am from always contains a languages level with a skill level (e.g. German A1, English B1)

So yeah interviewers can suck at their job.