Duo is not very clever about assigning sentences to skills. It sees a word (mangiate) which looks like a (feminine plural) past participle (mangiato), so it decides to throw the sentence to the desperate learners practicing the "Present Perfect" skill.
In this sentence "mangiate" is actually (second person plural) present indicative. As PATRICKPIZ1 said in response to Ronaldo-Correia, Italian presente indicativo tense works in a lot of cases, including most uses of present continuous in English.
The person adding this sentence felt that the most obvious meaning of the sentence is covered by the English present continuous. This does not preclude translations using present simple and they should be accepted as well.
yes, present tense can be used as a future tense it can even be used in simple past tense in specific sentences. it is very versatile. if the action is imminent (our sentence) it can be 'will you eat?' if the action is certain to occur, if it is an invitation to a future event, and after some conjunctions like 'non appena', 'fino a quando', 'se' and others. there are other conditions under which it can be used as a future tense. if you have a good grammar, it will list these conditions..
this book of verbs has a grammar starting on page 2. http://ge.tt/6fDnguA2/v/0?c
It is my own doubt (I'm italian mother-tongue). The translation that Duolingo offers is wrong. "Quanti panini mangiate" uses an analogue of the present simple conjugation (in italian it is called "presente"), but the English translation is in the present continuous (it is like an italian "gerundio"). The difference between the phrase in italian and the corresponding in English is that (in italian) the question can be generic, something like "usually, how many sandwich do you eat?", but in the English version is specific like "in this moment, now, while your mouth is full of sandwiches".
the sentence above is in the Italian present tense. the answer would also be in the same tense. it is used like the English present continuous. the present tense in Italian does a lot of heavy lifting. it is used to state a fact that is always true, ongoing events in the present (the sentence above), regularly repeating actions (habitual) occurring in the present, actions that began in the past but continue into the future, after some conjunctions (appena, fino a che, se) it can be used for future actions. there are others. a good Italian grammar lists the many uses of the present tense. Langenscheidt publishes a pocket size grammar that is pretty complete. barron; Collins; practice makes perfect also have Italian grammars. I don't know why this sentence is in this section.
How many sandwiches are you eating is not something that necessarily started in the past. In English it can mean how many sandwiches do you want. I think there is nothing much to be gained by throwing this sentence in this section. I hope this is not an indicator of the course going forwards.
this is one of the uses of Italian present tense. here is a site to help with this. https://www.fluentu.com/blog/italian/italian-present-tense/ and another. https://www.thoughtco.com/italian-present-tense-2011712
no. it's present tense used (appropriately) as present continuous. here is a page that will help. https://www.fluentu.com/blog/italian/italian-present-tense/
I dont understand why quanti panini mangiate means "how many sandwiches do you eat" but quante ragazze mangiano means (according to a previous lesson) "how many girls are eating". Why wouldnt the second example mean "how many girls are they eating?" Is it just based on context?