What is your favourite section in a supermarket?
My favorites sections in a supermarket are dairy and frozen foods .
My favorites sections are dairy and frozen foods (sections).
- Adjectives in English are always singular, even if the nouns they refer to are in plural. However, the word "favorite" can also be a noun (un sustantivo, e.g. "The swiss and venezuelian singers are my favorites to win the contest.").
- The word "food" is usually an uncountable noun, except when you're specifically referring to more than one type of food, e.g. "I like frozen, raw and spicy foods." or "My favorite foods are brazilian and mexican.".
- Writing "sections" twice was unnecessary. :P