The program seems inconsistent in the use of the article before the noun. Here it marks you wrong if you didn't use 'il' before 'latte'. And in other examples given in the lessons, like 'Lei beve latte' or 'Gli uomini bevono birra' there is also an inconsistency with no rule given to indicate if or when to use or not to use the article.
This blog offers a little insight, but I'm having trouble with this concept too. Maybe practice will reveal the nuances? http://blogs.transparent.com/italian/using-the-definite-article/
I have a question: are definite articles mandatory before uncountable nouns? For example, "io bevo caffè" vs. "io bevo il caffè". I'm Brazilian, and in Portuguese we can use both, but the first sentence indicates a general/nonspecific idea ("eu bebo café", similarly to English); the latter indicates something very specific ("eu bebo o café", the coffee in that cup, or from that package). I often come across the idea that both sentences are completely ok in Italian, regardless of its specificity. Is it true?
I'm sure this is has been addressed, too many comments to find. What's with the "il" before "latte', "Voi bevete il latte", shouldn't that read, "You drink THE milk?" I'm so confused. Sometimes it yells at you if you put "the" and sometimes it yells at you for not putting in the sentence. Sheesh \m/