What's up?

USAGE SUMMARY

"What's up?" is correct and usable in written English
It can be used as a casual greeting, similar to "Hello," or "How are you?". For example, "Hey there! What's up?"

✓ Grammatically correct

News & Media

Wiki

Academia

Social Media

Human-verified examples from authoritative sources

Exact Expressions

32 human-written examples

What's up Walker's sleeve next?

Forbes

What's up?

The New York Times

What's up there?

The Guardian

"What's up, New York?

The New Yorker

"What's up everybody?

Los Angeles Times

"What's up, beautiful?

Huffington Post

Human-verified similar examples from authoritative sources

Similar Expressions

28 human-written examples

What was up?

The New York Times - Arts

What is up?

The New Yorker

What is up for grabs?

Independent

What was up with that?

The New York Times

What is up there?

The Washington Post

Expert writing Tips

Best practice

Treat it as a rhetorical greeting; in many contexts, a detailed answer is not expected, and a simple response like "Not much" or "Hey" suffices

Common error

Avoid using this phrase in academic papers, formal reports or when addressing high-level officials for the first time. Its inherent informality can be perceived as a lack of professionalism or respect in rigid social hierarchies.

Linguistic Context

In linguistic terms, "What's up?" serves as a phatic expression, a phrase used primarily for social signaling rather than for conveying information. As noted by Ludwig, it functions as a greeting that acknowledges the presence of another person and opens a channel for further communication.

Expression frequency: Very common

Frequent in

News & Media

75%

Wiki & General Knowledge

15%

Academia (Interviews/Sociology)

10%

Less common in

Formal & Business

5%

Science

3%

Legal Documents

1%

Ludwig's WRAP-UP

In summary, "What's up?" is a quintessential piece of modern English idiom that balances multiple roles: it is a greeting, an inquiry and a phatic social tool. Ludwig AI correctly identifies it as a valid and correct phrase within its intended informal register. The wealth of examples from authoritative publications like The New York Times and The Economist confirms that while the phrase is casual, it is a standard fixture in professional media for capturing authentic human interaction. Writers should feel confident using it to add personality to their dialogue, provided they maintain awareness of the appropriate social context and avoid it in strictly formal environments.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

How is it going?

Slightly more descriptive of the person's current state of being

What is happening?

More focused on current events or activities around the speaker

How are you?

The standard formal or neutral equivalent of the greeting

What is new?

Specifically asks for recent updates in the listener's life

How have you been?

Inquires about the time elapsed since the last meeting

What is the matter?

Used when the phrase implies concern about a potential problem

What is going on?

Often used to demand an explanation for a situation

Are you alright?

Shifts the focus entirely to the listener's well-being

How are things?

A broader inquiry into the general state of the listener's life

Sup?

An extremely abbreviated slang version used in texting

FAQs

How to use "What's up?" in a sentence?

You can use it as a standalone greeting, such as "Hey John, "what's up"?" or as a way to inquire about a problem, like "I see you are upset; "what's up" with that?"

What can I say instead of "What's up?"?

You can use alternatives like "how are you doing", "what's new" or "how is it going" depending on the context.

Is "What's up?" formal or informal?

It is decidedly informal. While common in media and casual speech, more formal settings usually require "how are you" or "good morning".

What is the difference between "What's up?" and "How are you?"?

The main difference is the register; "how are you" is polite and neutral, whereas "What's up?" is casual and often used among friends or peers.