Alicia O. answered 10/24/20
Bilingual Tutor- Focus on Spanish Language and Literature: K-12
Hello! Yes, for this example you would say "la mantequila." Mantequilla is a feminine word, so your options would be "la" or "las", but since this is singular your answer would be "la." Remember that there are still exceptions though ! And not every word that ends in -a is feminine, just as there are words that don't end in -a that are feminine :) I hope this helped!
Howard S.
10/23/20