1) Is there a difference between saying: Aより、Bの方が好きです。and: Aより、Bが好きです。I believe I've seen both versions in my grammar schedule.
2) Is there a difference between saying: ではありません and: じゃないです。 (I assume it has something to do with formality/politness, but which should be used when exactly? Do English "formal situations" always correlate with Japanese "formal situations"?)
3) There are two sentences in my schedule:
スキーしたことある？
スキーをしたことがありますか？
Is it often possible to simply leave out the particles like it's done in the first sentence? What are the boundaries of this possibility?
i apologize if any of these questions have already been answered in a place I did not know of yet!
1) Afaik there isn't a whole lot of difference, with Aより、Bの方が好きです here you have more of the comparison nuance being represented. I feel like I hear more of the 方が好き though, as in for exemple someone shows you oranges and apples and asks you which you like more, you'd just say リンゴの方が好き
2) The meaning is the same, like you said the difference is formality. Nowadays I know for a fact textbooks and teaching materials tend to teach the じゃないです first (that's also how I learned it) while a few years ago it was ではありません. You'd use ではありません more in formal, business and written whereas じゃないです can be conversational.
3) You can leave out particles like it's done in the first sentence, what happens though is that formality drops. With your friends and family you could use the first sentence, however with teachers or higher ups you might want to use the second sentence. I'd say the boundaries are simply knowing when to use formal speech vs casual speech depending on who you talk with. Both sentences are correct though.
