ASK A QUESTION Why Cuáles and not Cuál?
For the question "What are your favorites?" the Google translation is: "¿Cuáles son tus favoritos?" Why Cuáles and not Cuál?
Cuáles is the plural form of cuál.
Your question asks for a reply in the plural. You asked "What are you favourites." Both "are" and "favourites" indicate a need to use cuál in the plural.
I hope this is some help to you.
Because favorites is plural, therefore cuáles must be plural.
"Cuáles" is for plural words, such as favorites, where as cual refers to singular objects like, ¿Cuál es la fecha?
¿Cuál es tu favorito? = Which is your favorite? ¿Cuáles son tus favoritos? = Which are your favorite?
Hope this helps "patkendavido"...
Presumably because your answer is expected to be in the plural.