I was asked a question in Spanish where it was expected for me to answer in Spanish. Except for that one question, the rest of the interview was conducted in English. I marked “fluent” on my application so they may or may not do it for lower levels of proficiency. I think if you marked another language (except maybe creole) they will likely not assess it. A massive portion of their patient population speaks only Spanish so I think some interviewers (particularly those who are fluent in Spanish) may be motivated to check that people aren’t inflating their proficiency in the language and would actually be able to communicate with Spanish-speaking patients if they mark a high level like “fluent.”