Mixed language slides

I have a course that is in English but one slide has a couple of sentences in Spanish. Our accessibility reviewer told me: "There is text on the slide that is in Spanish that is not programmatically specified as Spanish. This is causing the screen reader to read the Spanish as though it was English. The language of the text should be programmatically determinable, so changes in the language should be identified in the code. "

Is doing this possible, and if so, what does it involve? #notaprogrammer :)

Thanks!