A clueless rookie could pick up how their boss wrote an email, when a coworker switched from a quick message to a more formal one, or what someone meant by “run it up the flagpole.” But Gen Z entered a workforce where much of that learning can happen through a screen—and where language on either side of it isn’t always translating.

Knowing how to “speak office” has never just been about understanding the words your coworkers use. Workplaces come with unwritten rules about how to formally address someone, what belongs in an email instead of a Slack message, and even how familiar you can be with someone you just met. Gen Z began learning those rules as the pandemic and remote work scrambled the ways they had traditionally picked them up, while social media and instant messaging brought different communication habits to work. And of course—AI, as the kids would say, has “entered the chat” as another way to learn too.

The apparent language divide between generations is more complicated than whether boomers know what “delulu” means. The words are changing, but so are some of the rules around how people communicate at work, and not everyone agrees on what sounds appropriate or professional anymore.

It seems so silly on paper. Gen Z has “delulu,” “rizz,” and “no cap.” Older workers have “blue-sky thinking,” or brainstorming without practical constraints; “move the needle”; and the particularly puzzling “boil the ocean,” or taking on an impossibly large task. They’re noticeable enough that someone has now built a translator for them.

Sunny Workplace, a nonprofit employee engagement platform, recently launched WorkGen Translation, an online tool that decodes slang, idioms, and workplace jargon across age groups. 

This year, the company commissioned Censuswide to survey 2,004 U.S. workers on May 25 and 26, split evenly between Gen Z and boomers. Eighty percent of the 1,002 Gen Z respondents said generational differences in workplace language were a challenge, compared with 30% of the 1,002 boomers surveyed. 

The confusion goes both ways. Among specifically boomer respondents, 76% said they had no idea what “delulu” meant, 66% said the same of “rizz” and 61% of “no cap.” Gen Z respondents had their own trouble with corporate speech, with 22% said they knew exactly what it meant to “boil the ocean,” while 25% said the same of “blue-sky thinking.”

The misunderstanding that matters at work can be much more mundane. Betsy Sneller, an assistant professor of sociolinguistics at Michigan State University, pointed to something nearly every office worker uses: email.

“Younger folks entering the workforce don’t really have the genre of email in the way that older speakers do,” Sneller told Fortune.

Older workers are more likely to treat email as a relatively formal and permanent form of communication, Sneller said, while reserving Microsoft Teams or other instant messaging platforms for quick exchanges. 

Younger workers who grew up communicating through social media and messaging apps may not make the same distinction. That can mean skipping a formal greeting or punctuation in an email without giving it much thought.

“There can be sort of miscommunication where younger folks are being casual in an email, maybe not using punctuation, maybe not using a formal salutation, and it gets interpreted as very rude by older speakers,” Sneller said.

The unwritten rules of ‘speaking office’

A linguistic concept behind some of that disconnect is called a register, which focuses on how language use changes based on social context and audience. 

“We have a work register, we have a home register,” Renée Blake, an associate professor of linguistics and social and cultural analysis at New York University, told Fortune.

People routinely change how they communicate depending on where they are and whom they’re talking to. Home might allow one way of speaking; addressing a large group or reporting the news might demand another. Work has traditionally come with its own expectations. Blake sees what happens when those expectations collide in students’ emails. Instead of an introduction like “Good morning, Professor Blake,” she sometimes gets a simple “Hey, Renée.”

“Am I your friend? I’m not your friend, and you don’t know me,” Blake said with a laugh.

The issue isn’t simply that one way of speaking is right and another is wrong. Registers come with rules people become accustomed to, Blake said, and when someone steps outside the register expected in a particular setting, it can feel as though that person is breaking the rules of the space. 

That’s where communication differences can become a judgment about the person doing the communicating. Iain Smith, head of behavioral science at Sunny Workplace, said that can be particularly consequential for workers who are still learning the language of their workplace.

“If they haven’t learned the workplace vernacular, and they speak using phrases like ‘delulu’ and ‘rizz,’ for instance, I think there are judgments that can be made about professionalism based on that,” Smith told Fortune.

For younger workers, learning what those unwritten rules are may also look different than it did for the rookies who came before them.

“They’re not necessarily now sitting next to someone who’s been doing the job for 20 years and learning the shortcuts and the hacks and the little ways of coping with a stressful day,” Smith said. “They’re turning up to Zoom.”

It’s not just the kids

Gen Z entered work during that upheaval, but they weren’t the only ones adjusting to new ways of communicating; it’s more complicated than it looks.

“COVID also stunted all of us,” Blake said. “It’s not just young people.”

Workers across generations suddenly spent extended periods communicating from behind screens, and many returned to offices only partially, if at all. At the same time, technology increasingly competed for people’s attention as they figured out how to interact with one another again.

Blake experienced some of that confusion herself. After getting sick, she moved one of her college classes online and assumed she could be more informal with students she had only recently met. Some of them thought otherwise.

“This is too much, this is too informal. You don’t know me,” Blake recalled them telling her. “So this is going the opposite direction,” she added.

Even AI is becoming part of the negotiation. Blake said she sees young people using AI to learn forms of professional communication they haven’t necessarily been taught, including how to write more formal correspondence. But outsourcing that learning comes with its own tradeoff: The result can sound stiff, templated, and impersonal.

Changing ways people communicate don’t necessarily mean generations themselves are as different as workplace stereotypes suggest. A meta-analysis published in the Journal of Organizational Behavior found few systematic, meaningful differences among generations across a range of workplace outcomes.

Smith, a millennial, remembers when his own generation was the subject of sweeping theories about how it would transform—or ruin—the workplace.

“From a scientific perspective, there’s a lot of research out there that shows that actually generational differences in work values, work-life balance, stress, burnout, working preferences are all overhyped,” Smith said.

Sneller nevertheless believes communication styles between people entering the workforce today and those already in it are more pronounced than in the past. She pointed to a combination of social media and the pandemic, and sees some of the effects in her own classroom, where students sometimes need more encouragement to begin casually talking to one another.

And the line between the generation that needs translating and the one doing the translating doesn’t stay put for long. Sunny’s survey asked workers about Gen Alpha slang, offering Gen Z an early taste of being on the other side. Forty-one percent of Gen Z respondents didn’t know what “Ohio” meant, while 75% didn’t fully understand or said they wouldn’t use “skibidi.”

So Gen Z may not have to wait until middle age to start wondering what the kids are talking about—they may just have to wait for Gen Alpha to clock in.