Check out the TedX talk on the guy who helped come up with DL, but the short of it is by using DL we are helping to translate the internet into the language we choose to study. I think that's why we get such interesting sentences rather than the lame ones that exist in textbooks that help you learn a language. It's really an innovative business model as well.
In this case, i wonder if it's similar to Spanish where you pretty much always use estar (stare) with adverbs. Adjectives can be used with either estar/ser (stare/essere), with different nuances in meaning. I'd guess that in "stavo meglio", meglio is used as an adverb to modify stavo (sorta like saying my situation was better, my "being" was better) whereas if you said "ero meglio", meglio is an adjective, meaning it doesn't modify the verb (ero) but rather the subject of the verb. So you were a better person (or better at something) before.
So maybe you'd say "stavo meglio prima" to say that you felt better (your situation/condition of "stare"-ing was better) before but now you are sick again and you'd say "ero meglio prima" to talk about yourself, maybe you used to be a great soccer player but now you aren't.
No, it is not the same as Spanish, unfortunately; otherwise it would be rather simple to understand it, but Italian always likes to mess things up. The examples you gave are totally correct, but in Spanish, you would say: "Estoy triste", which you cannot say in standard Italian ("sto triste"); the latter would be regionally marked. So, it's similar to Spanish but not exactly the same. In Spanish, "Estoy en su casa" (I am at his/her/their house) wouldn't get the exact same meaning in Italian if you used "stare". In standard Italian: "Sto a casa sua" vs. "sono a casa sua" mean two different things. The former means that the speaker is staying at the other person's house (maybe for a few days), the latter means that the speaker, at the time of the sentence, is in the other person's house; it doesn't imply anything more than that. In the South, where I live, because of the influence of regional languages, such as Napolitan (close to Spanish), people use the two previous sentence as synonyms, which are not in Standard Italian.
Maybe i'm wrong, but I think "senza di te" would be more like "without your presence" (Physically. For exemple a mother whose son is on a trip ; or if I had dinner every night with you and one day you'd miss and i'd have to have dinner "senza di te")
And "senza te" would be more like "Without you" (Generical. Could be physically or just the idea of being a part, like a a couple that have just broken up).
Wiktionary says that use of "bene" as adjective is limited - usually to descript upper-class, posh, high class things. So, in general, if it's an adverb, use bene & meglio (which are both invariable even as adjectives), and if it's an adjective use buono/a/i/e , il/la migliore, i migliori, le migliore
To my ear, right now I'm hearing three different pronunciations of "e": 1. The "ay" sound when "e" is at the end of a word - "prendare" 2. The "eh" (as in "pet") sound in the "e" in the middle of words - again, prendare 3. An "e" which is in-between - forming the mouth to say "ay" but saying "eh" instead. [To do that, you say "ay" but don't move your tongue, jaw and lips at the end of the syllable, leaving everything in the "ay" shape, then try to say "eh".]
The "e" in "te" sounds to me like it's the 3rd version. Comments, anyone?
There are only 7 Italian vowel sounds: (/a, i, u/) plus two variants of e/o: close-mid (/e, o/) and open-mid (/ɛ, ɔ/). Usually the close-mid (/e, o/) variant is pronounced, except in the stressed position which defaults to the second-to-last syllable. When stress is indicated by a diacritic (usually only on the last syllable), the grave accent (è, ò) indicates open-mid (/ɛ, ɔ/) sound, while the acute accent (é, ó) indicates close-mid (/e, o/) sound.
Rules like this are great guidelines, but if they are really they way Italian is supposed to be pronounced, then the people speaking the audio tracks here are often very far off. Often, the nuanced sound of vowels is shaped by the surrounding consonants. A good example is the verb "sono". If you say the first "o" exactly the same as the last "o", it doesn't sound like the audio - the second "o" is without doubt a long sound (like "oh"), while the first "o" has a slight shortening nuance redolent of the short "o". Exaggerated, it would be "Saw-Noh", except the first syllable has much more of the "oh" sound, just backing slightly off the strong "oh" of the 2nd "o".
There are a lot of examples of these minor variations in the pronunciation that I hear. Unfortunately, the slowed-down versions of words has a very different pronunciation from the faster version, so I don't know how useful that is. If I'm not sure, I copy a phrase and paste it in the translator module at reverso.net, which has a pronunciation feature.
I'm an amateur violinist, and my ear is training to hear some very minor differences in tone, pitch, and timbre, so many I'm hearing stuff that a lot of others don't hear - yet.
That makes it even more curious. My suspicion is that the original source for the words are real people - the tones are not 100% computer generated. If there were software-created rules for pronunciation, it seems to me that the sounds would be consistent, and they just aren't. As such, they sound more authentic - like the words are read separately by real people, recorded, then pieced together to form sentences. It's the amount of variation in sound that leads me to conclude that there's a lot more human input in the generation of the sound.
I really do hear differences in the sound of the two "o" sounds in "sono" and "loro". When I pronounce the words, the differences seem quite natural, shaped by the nearby consonants, or the fact that the second "o" is at the end of a word. (Those are the "purest" form of the "long" or "closed" "o"-sound.