This is a simple yes or no answer. The interviewer may ask this question, depending on the diversity of their clients. Unless stated in the job posting, this is likely not a deal breaker but more a question of interest.
"In addition to being fluent in English, I speak conversational Spanish. I've found my ability to speak Spanish helps during patient exams from time to time."
"I do not speak any other languages, aside from English. Would you like for me to learn another language? I have wanted to commit to expanding my linguistic skills."
"In my current position, we have many clients to speak a variety of languages. Although I am only fluent in English, I do have basic skills in Spanish, French, and Cantonese."