"Thank you? You're welcome"
I thought "ti prego" was how to say please, like a synonym for "per favore." Does this mean that "Prego" can mean either? I'm assuming, from this, that it depends on the context, like how the word "mañana" can mean "morning" or "tomorrow," in Spanish. I'd appreciate a correction, if I'm on the wrong track.
"Ti prego" means "I pray you", and it's the verbal equivalent of prostrating yourself in front of someone; a favourite of little children begging their parents alongside "ti supplico", I beg you. "Prego" is another beast entirely, and used in totally different contexts (more than a few, unfortunately for students).
Edit: To be fair, in formal speech "La prego di" + infinitive, and in bureaucratic speech "È pregato/a di " + infinitive are indeed the equivalent of a "please".
I wonder if there is another expression in English for "You're welcome". With same meaning (no need to thank me). I can not remember what I learned at school. I think it's such a weird expression that I have to come up with a story to remember it and only the last part is said out loud: "(I did it for you with pleasure. If you need me again for the same, then) You're welcome". Can a native speaker answer this, preferably from the UK?
No, Italian doesn't use the upside down question mark. As far as I know, Spanish is the only language in which this punctuation mark is used; in Spanish, the upside-down question mark stands for the beginning of the sentence (question) and the regular question mark after the sentence.