The interviewer is interested in what you are currently capable of and what potential you might have to develop additional language pairs that could ultimately be added to your portfolio. When responding to this answer, consider sharing the direction in which you translate as well. For example, you might primarily translate into your native language, not out of it. When providing additional spoken languages, be sure to include your proficiency level. If you took Spanish several years ago, and you don't remember most of what you'd learned, then let them know you have an elementary proficiency - you don't want them to assume you're fluent if you aren't. You might elaborate even further by displaying your interest in enhancing your fluency in order to add to your translation portfolio.