"You don't like mangoes?"
Translation:ʻAʻole ʻoe makemake i ka manakō?
My feeling is that when talking about them in general, english likes to say "bananas (plural)" while hawaiian prefers "the banana (singular)". Hence "You do not like mangoes?" using ka manakō. But if you were asking if the person does not like the mangoes here on the table that they are eating right now, you might use nā manakō?
Do you like the mangoes?
It implies a specific set of mangoes. Contrast with:
Do you like mango?
It's asking, in general, is mango a fruit that you enjoy? It's like asking "Do you like pie?"
That may not be the reasoning in Hawaiian, but it's a useful way to remember it, coming from English.
I think this is where we need to get into the head of the native language. It might conceptually translate as "the fruit called mango." I hear a similar thing coming through from a native Mexican-spanish speaker. She will say "he likes the mango" instead of "he likes mangoes." For me, this is one of the delights in learning a different language - learning how a culture conceptualizes. So, often I try to learn "the phrase" first, and see how I need to adjust my English to translate conceptually. Then it's easier to do it right, and I'm not trying to apply English rules or concepts to the new language I'm learning. Just food for thought from a fellow learner.
Because you're talking about the food in general, not how many you don't like. Ka is general indication of a noun. Nā is plural. When we say in English "I don't like mangoes" that is how English handles a general category of something. Simply two different ways of expressing the idea. No word for word translation with this particular thought concept.