Please Duolingo, decide if you want these kind of sentences to be translated as a present perfect (He/She/It has done) or as a passive voice (He/She/It is done). I think you shouldn't mix the things, because these lessons are for studying the present perfect (passato prossimo) in Italian, not the passive voice. Don't generate confusion please.
But we can use this lesson to practise past participle forms even for sentences without passato prossimo.
The sentence is not ambiguous (as has been remarked above, "has done" would be "ha fatto"). And I actually prefer if duo makes us think instead of blindly assuming since it's a lesson about passato prossimo, all sentences must use this tense. This will make us pay more attention to the difference between passive forms and active forms of verbs that happen to use essere as their auxiliary.
In English, "done" can be used in various ways as a verbal adjective:
- The hamster was eating. It is done. (It = the hamster)
- He was cooking the rice. It is done. (It = the rice)
- You asked me to feed the fish. It is done. (It = the action of feeding the fish)
Is the same true for "È fatto."? If so, could "È fatto" also be translated as "He is done."?
In case you are wondering why I don't mention passive voice and what I mean by "verbal adjective":
In Tips and notes for passato prossimo, Duolingo indicates that the past participle can be used as a verbal adjective (and as such can be declined in gender and number). The past participle can be used as an adjective in English as well, resulting in constructions with the same wording as passive voice but with a different meaning. Consider the following examples:
(1) "In this recipe, the rice is cooked in an oven."
(2) "The rice is cooked, so let's eat."
Example 1 uses passive voice and simple present tense. It could be paraphrased as "In this recipe, one cooks the rice in an oven." The simple present tense is used because the time of the action is indefinite. In example 1 the verb = "is cooked."
Example 2 uses "cooked" as a verbal adjective. This kind of adjective describes a state or quality that results from an action. In this example, the cooking occurred in the past, but the sentence is making a statement about the present condition of the rice. In example 2, the verb = "is."
The above examples show that "is cooked" can be either (A) a passive verb in present tense or (B) an active verb in present tense + a past participle acting as an adjective. The same is true for "is done." However, given the sentence "It is done." without context, most native speakers will understand "done" as a verbal adjective. With a bit of a stretch, I can produce examples using the passive voice "is done":
(3) "Should I go to the wedding wearing these clothes?" "It is done."
(4) "Should I go to the wedding wearing these clothes?" "It is not done."
Although grammatically allowed, such use of the passive voice would be atypical for a native speaker of English -- so atypical, in fact, that a native speaker might interpret the reply in sentence 3 above to mean "The wedding has ended, so the question is irrelevant." rather than "Sometimes people wear clothes like that to a wedding." The use passive voice is perhaps more obvious in sentence 4, particularly if we imagine the response being said in a haughty voice.
It is the passive voice - look here: http://tutorino.ca/grammatica/2007/7/17/the-italian-passive-voice-la-voce-passiva.html
Past participles (like fatto) do behave like adjectives (they agree in gender and number), but they are the main-verb part in constructions like:
- avere fatto (passato prossimo)
- essere fatto (diatesi passiva)
Outside of such constructions past participles can be used like normal adjectives:
- un lavoro fatto