What's up? / Sup?

• A colleague, friend or barista greets you with it and you need a reply now.
• You want to greet someone informally yourself, and you're not sure it's safe here.
• Someone says it to you mid-conversation with a concerned face — a different move entirely.
• You're about to greet a client and the American media version is the one in your head.

• What is up? — /wɒt ɪz ʌp/ · never said as a greeting. Only literal: "What is up there?"
• What's up? — /wɒts ʌp/ · informal · the standard form
• Whassup? / Wassup? — /wəˈsʌp/ · casual · eye-dialect spelling of the same thing
• Sup? / 'Sup? — /sʌp/ · very casual · clipped further; young, male-skewing
• Whaddup? / Wagwan? — slang · AAVE and British-Caribbean · recognise it, don't borrow it

• Linking: the t + s + vowel run together into one unbroken chunk. One stress, on up.
• Reduction: what's up → 'sup → sup. Deleting everything before the stressed syllable is a normal pattern, not laziness.
• Sup therefore isn't a different word — it's what's left of this one.

"WHAT. IS. UP." — three equal stresses, no linking — is the clearest tell of a non-native speaker using this phrase. If you can't say it fast and linked, use "How's it going?" instead.

• "Hey, what's up?" — "Hey man, not much. You?"
• "Yo, what's up?" — "Not much. Same old."

It's the first thing said. Light, rising intonation, no eye contact needed, speaker is relaxed and moving.

• "You've been quiet all morning. What's up?"
• "What's up? You look worried."
• "Hey — what's up with you today?"

Comes mid-conversation, often after a pause. Slower, lower, falling intonation, direct eye contact, concerned face. If you were already talking, it is this one.

• "Hey, what's up? I got your message." — "Not much, just wanted to check about Friday."
• "So what's up with the Johnson project?" — "The client pushed the deadline back."
• "What's up this weekend?" (= what are the plans)

Opens a call or a thread with a topic attached. The extended form what's up with …? is always this or the previous sense — never a greeting.

• "Sup?" / "'Sup?"
• "Yo, what's up?"
• "Whassup!"

• "Hey, what's up?"
• "What's up, man?"
• "Hey — how's it going?"

• "Hi, how's it going?"
• "Hi Anna, how are you?"
• "Morning — how was your weekend?"

• "Good morning. Thank you for making the time."
• "Good afternoon — it's a pleasure to meet you."
• "I hope this email finds you well."

• "Hey, what's up?" — with someone you know
• "Hi, how's it going?" — with everyone else

• "Morning, all."
• "Hey — what's up?" (casual team only)

• "sup" — a dev you know well
• "hey, what's up? quick q about the deploy"
• "hey — got a sec?"

• "Hi Anna," / "Hi Anna, hope you're well."
• "Good morning Anna,"

• "Hey, what's up?" — with a nod
• "Alright?" — British, same job

• "Not much." ← the default
• "Not much, you?"
• "Nothing much." · "Not a lot." · "Same old."
• "Not much, just working." · "Chilling. You?"
• "Hey, what's up?" — mirroring it back is completely acceptable

• "Nothing, I'm just tired."
• "Yeah, I'm alright — long week."
• "Actually, do you have five minutes?" — if you do want to talk

• "Not much — just wanted to check about Friday."
• "Yeah, so the client pushed the deadline back."
• "All good on my side. You?"

• "Not much — why, what's up?" (hands it back, works for all three)
• "All good. Everything okay?"

• What's new? — genuine light request for news
• What's going on? — greeting or real question — the same ambiguity
• What's happening? — casual greeting, slightly dated
• What's good? — AAVE-origin greeting, now broader slang
• What's the story? — Irish greeting
• Alright? — British; a greeting, not a question about your health

• What's cracking? / What's poppin'? — slang, dated-trendy
• How's it hanging? — crude, male
• What's it to you? — not a variant — this means mind your own business
• What of it? — not a variant — confrontational: so what?

• The Budweiser "Whassup?" ads (1999–2002) — made the phrase globally famous. An exaggerated drawl is someone quoting a 25-year-old commercial, usually ironically.
• WhatsApp — is named after this phrase — "What's up?" → "WhatsApp". You already type it every day.
• "What's up, Doc?" — Bugs Bunny. Occasionally used as a joke greeting to a doctor or a PhD.

• ❌ "What's up?" → "I am currently debugging a webhook integration and my landlord called about the—"
• ✅ "Not much, you?"
• The status report. Treating the greeting as a real question is the single most common error — nobody wanted the news.

• ❌ "I'm fine, thanks."
• ✅ "Not much, you?"
• That's the reply to How are you? What's up? asks about events, not your state — the mismatch marks you as a learner instantly.

• ❌ "What is up?"
• ✅ "What's up?"
• It has to be contracted. The full form is only literal ("What is up there?").

• Reading it as «Що трапилось?» / «Что случилось?». It usually isn't — default to greeting-mode unless the context says otherwise.

• Answering with real news because «Як справи?» invites it. "Not much" is correct even on the most eventful day of your life.

• Using it with clients because it's the greeting you hear most in American media. Media English is casual English — use "Hi, how's it going?"

• Missing the concerned version. If a colleague says "Hey… what's up?" slowly after you've been quiet, they're asking if you're okay. A bright "Not much!" is a small social miss.

• A: Yo, what's up?
• B: Not much, man. You?
• A: Same. You watching the game later?

• A: (quiet, staring at their screen)
• B: What's up?
• A: Nothing, I'm just tired.
• B: You sure? You've been quiet all morning.

• A: Hey, what's up with the staging deploy?
• B: Yeah, the migration failed. I'm on it.
• A: Need a hand?

• ❌ "I'm fine, thanks." — answers a different question; the clearest learner tell there is.
• ❌ "What is up?" — nobody says the uncontracted form as a greeting.
• ❌ "What's up?" — to a client, on a first call, or in any email — too casual for all three.
• ❌ "Sup?" — unless it's already your natural register; in a non-native accent it draws attention rather than blending in.
• ❌ "Nothing! Everything is very good, thank you!" — over-answers a greeting that wanted four words.