I think they are introducing this now because we are learning the word "sei" as "(you) are," and they're pointing out that the same word can mean something else. This happens throughout the lessons. It can be frustrating, but it is helpful. (Otherwise I find myself thinking I'd remembered the original word incorrectly, rather than realizing that the same word has two very different definitions. )
This is one of the major things, that annoy me with the training: You never know when they suddenly introduce a new word without ever giving you an explanation for it. Especially with words that are spelled identically to ones you already know, it would be nice if they were highlighted... Like "alle" was in this sentence.
Indubitably! I'm not sure what it does when I "peek" at words I already should know, but the way it's set up makes me think I lose points at them or something. To lose points on numbers I have never been given, just because they are spelled identical to words I already know, isn't fair.
Even if it's not taking points away, it feels like it's trying to shame me. And I do tend to guess on new words rather than peek right away, unless I really can't think up a guess given the context, and here I would've guessed horribly because there's just no way to realize it's a number because there have never been any numbers yet!
Treating learning as a competition absolutely can help improve your retention. People have different ways of studying and this is mine. Besides, after working with different languages for a couple of decades, I've come to the conclusion that you should try to challenge your brain to figure out things through context and not take the easy way out by peeking - this keeps the brain actively involved in the act of learning. Passive learning isn't nearly as effective.
I don't know about the first question, but when you're saying something occurs at a specific time, you use the preposition "a" contracted with the article.
There are two ways to ask the time: Che ora e'? and Che ore sono? E' mezzogiorno--It's noon E' mezzanotte--it's midnight E' l'una--it's 1:00
For the rest of the hours, you use "le". Le refers to the word "ore" (hours) even though it's omitted: Sono le (ore) due. It's 2:00
So, if you want to say "at 2:00", it would be a+le due= alle due If you want to say "at 1:00", it would be a+ l'una=all'una Hope that helps.