Um guia para quem estuda Inglês Online
Pergunta: ''I don't really know a good answer to this sentence.''
''I often hear "nothing much", "the same old thing", and "the same old same old". When people in this part of the world use the last version, it often sounds like this: "The same old same-oh". I sometimes hear the slangy answer: "Notta lotta". This is a distortion of "not a lot".''
''The most usual reply I hear is "what's up" (or more precisely "whassup") since "what's up?" is most often not an actual question but just a greeting, like "Hi" so you can just say the same thing back,''
''Often the reply to "what's up" is just "what's up"! I know it doesn't make much sense, but it's become sort of like saying "Hi" not a real question.''
''For many people, "What's up?" has taken the place of "Hello!" It is often not a genuine inquiry into what's happening with you. We say "Hello!" in response to "Hello!" People who use "What's up?" as a greeting are doing the same thing.''
- Wordreference - USA