Candy is plural and singular - candies is incorrect here. Even though you can technically count pieces of candy, it is considered a non-count noun. "Candies" is only used in specific contexts - similar to how "persons" is used in specific contexts, but "people" is usually the plural of "person."
Very good, I agree, hair = hairs, but we are being marked wrong to put an answer that is also correct.
As i understand it, the singular / plural decision for the possessive word (loro, in this case) refers to the people count ("their" = more than one person), while the gender differentiation (on other sentences) refers to the gender of the noun/object, not the gender of the person in possession.
I wanted gender to differentiate the person, as it does in English (his vs. her), but apparently (if i understand), in italian, you don't differentiate his from her. (Do i have that right?)
In other words, if you ask whose dog that is, and the response "it is his dog" and "it is her dog" would be the same answer. Did i get that right?
Please explain better why it is not mangiano, since the subject cani was plural.......thanks