¿Is it right to say "At all"? I was talking with a friend and she told me: I'm so old! I wanted to say: You're not old at all. Is it right and enough to just answer: "at all"? Or it should be "not at all"? Thank you!

How do you say this in Chinese? "Backing track / Music backing track" Thanks!

How do you say this in Chinese? "I just arrived in Argentina" Thanks!