In theory yes - you could use "Lei" which is the formal "you" if you were talking to the Queen of England but even then she wouldn't be very impressed because the rest of the sentence is pretty informal and it is from this informality that one understands, in this sentence, we are talking about "She." The capital "L" happens here not to indicate the formal "you" = "Lei" but simply to indicate the beginning of a sentence.
It could be formal you (it does work in the system) but the sentences here won't force you to use formal you unless it is clearly a sentence you would use with the Queen :) (for things like "La prego di..." or "Posso chiederLe..." we prefer you practice using formal you) If you see Lei at the beginning or middle of a sentence, do feel free to use you unless it seems preposterous in context.
Normally, I would have used 'she' unfortunately with the formal you being capitalised and at the beginning of this sentence, The formal 'you' complied with the intent of the section. I am sure it was a trick question by Duo to implant in our mindsthat the use of 'Lei' does not always rely on it starting with a capital 'L'.
I find this link very helpful in knowing when it is technically correct to use I vs me: http://m.wikihow.com/Choose-Between-%22I%22-and-%22Me%22-Correctly However, I never hear anyone talking in the technically correct way in cases like "You are much taller than I". I'm not even sure people would speak to the Queen of England like that -then again, I live in Australia.
Jack, properly so, but the vast majority of AE speakers wouldn't say it; they'd say: "than me" -- unless the verb were present: "than I am". My suggestion is to remember the English translation DL provides, even though you consider it incorrect, since it'll help you avoid the mistake of saying in Italian,: "...di io". If you want a language that mirrors your translation take up German.
Duolingo seems to operate by introducing new words in each lesson, often with more than one meaning (notice how we got the word "sei" meaning "six" before all the other numbers, because it's spelled the same as the word "sei" meaning "you are"). In some cases this is a nice feature because it forces you to think more, but in some cases (like the clitics lessons) I'd say it's too confusing.
Donnyw...You're correct of course, but I have to agree with carinofranco. Use of the objective pronoun, in this case, "me" is much more common than the subject pronoun. I suspect the day will come when it'll be considered the grammatically correct form to use in situations in which a verb is absent.
graniemhaol: You're of course correct, but the problem is no one says that in everyday colloquial English, unless the verb "am" is explicit. It's clearly fine to point it out, but there are two reasons in my mind for not only allowing/accepting "me", but in fact showing it as its primary answer: 1st it's what people say and if someone's trying to learn to speak English the way it's spoken rather than what's in grammar books, then Duo's correct in using "me"; secondly for those of us trying to learn Italian it's a lot easier to learn to use the objective pronouns in situations like this rather than subject pronouns if that's what we'd normally do in English.(me & you singular te -- otherwise Italian's like English). So go ahead and insist on "I" and then when expressing the idea in Italian watch how you'll automatically say "...di io".
I see your point but I believe that learners nonetheless should know the grammatically correct version. Otherwise this inevitably would cause confusion for them when they encounter it in written English. (Perhaps because I'm familiar with French & Spanish) I don't see any possibility of confusing 'di me' with 'di io' or similar. It's good to be aware of both, I agree. For me though, I admit it immediately jarred when I saw it written (as above).
I politely disagree. I've found that Duolingo also tries to teach by showing contrast. Throwing in the singular feminine is a way of demonstrating its similarity to the formal you, and therefore alerting us to be attentive. Just as in the section on the future perfect, it would put in a few simple future verbs - I assume just so we would recognize the difference.
Not if you accept the existence of disjunctive pronouns in English. https://en.wikipedia.org/wiki/Disjunctive_pronoun#%22It's_me%22
Unless you accept that "than" can be a preposition. See https://www.merriam-webster.com/words-at-play/than-what-follows-it-and-why
See my previous responses about the English disjunctive pronouns. In Italian one uses the 'stressed', or 'disjunctive' pronoun see, http://tutorino.ca/grammatica/italian-disjunctive-or-stressed-pronouns-i-pronomi-tonici.html (note paragraph 4). So no, it is not the nominative case in Italian.
True that in perfect English this sentence would end with "I" instead of "me." But it's so commonplace (at least in American English) to use "me" instead of "I." It flows better, and it all depends on of you want to be prescriptive vs. descriptive with your grammar. I tend to be more descriptive...the point of language is communication...if the idea was conveyed, then you were successful.