"Whassup?" is a very casual hello. It is a written-down way of saying "What's up?" the way it actually sounds in fast, relaxed speech — the t and the p run together into one lump. It is not a real question; nobody expects you to report what is happening in your life. It is just a friendly noise that means "hi", and the normal answer is another "whassup", or "not much", or "hey". You use it only with people you are close to — friends, classmates, a brother. Never with a teacher, a boss, a customer, or anyone older that you should show respect to. It carries a strong flavour: it came out of American speech, especially Black American English, and it got hugely famous in the late 1990s from a beer advertisement where friends shouted it at each other on the phone. Because of that ad, a lot of people now say it half as a joke, stretching it out — "whaaassuuup!" So be warned: if an older person says it to you, they are probably being funny on purpose. You will also see it spelt "wassup", "whazzup", or "sup" (just the tail end, even more casual). Its natural home is speech, text messages and chat, not anything written properly.

「嘿，幹嘛？」「最近怎樣？」——就是很隨便的打招呼，類似「安安」「欸」那種輕鬆語氣，不是真的在問你發生什麼事