"I eat chocolate ice cream."
Translation:Mangio il gelato al cioccolato.
That's exactly it. When you are talking about the generic idea, you use an article. That tells people you are talking about the general idea of something. "Mangio il gelato" just means "I eat ice cream". Similar concepts are used when saying "I like sports" [Mi piace lo sport] or "I like cats" [mi piace il gatto].
Because it is not literal translation of English. Nouns in Italian require an article before, therefore, you should put the article (il) before the noun (gelato). Chocolate ice cream translates as gelato al cioccolato because it is ice cream with chocolate in it, it is not made of chocolate (not in the sense of it being its base). A substitute in English could be chocolate flavoured ice cream.
Ummm I'm still unclear about definite article use in this context. How would one differentiate between eating ice cream generally, "I eat ice cream" which, if I understand correctly should be "Mangio il gelato" and eating a specific ice cream, "I am eating the ice cream" also "Mangio il gelato"?
al = a + il
so, you just need to determine when you need to use 'a' or whatever proposition you think is appropriate, and then add it together woth the appropriate article for your noun. Here are two helpful links:
al is correct here . I do not know Spanish, but in Italian, if the noun is actually the base of the thing being made, then you use 'di'
la zuppa di funghi
Whereas, if the noun is just describing a type, (think flavor-added) then you use 'a'
il gelato al ciocolato
here are helpful details: