- Okay, K-Pop stans, think of your favorite track by your favorite artist.

Got one in mind?

What language is it in?

Most likely, you said Korean, but if you were thinking about "Dynamite" by BTS, or "APT."

by Rose, or even "Golden" from KPop Demon Hunters, your answer might have been English.

Or, maybe like an increasing number of K-pop songs, the answer is somewhere in the middle.

So, what language does K-pop music actually use?

Linguists say that just like the sound of this vibrant and dynamic genre, it's always changing.

But even more surprising is how it could be changing you.

I'm Dr.

Erica Brozovsky, and this is "Otherwords."

(playful music) - Otherwords.

- So, how did Korean and English come together in a swirl of sugary pop music in the first place?

Much of the time that two languages bump up against each other, it's because they're physically adjacent.

Think the Spanglish spoken around the US-Mexico border, or Portunol, a hybrid of Portuguese and Spanish found in the Iberian Peninsula and at the border between Uruguay and Brazil.

And close proximity is how English and Korean started coming into contact, too.

The Korean War brought a large US military presence to the region, establishing many military bases, some of which still exist in South Korea today.

American soldiers interacting with Korean locals started introducing English loanwords like "computer" and "ice cream" into the Korean lexicon.

But these American soldiers also brought American music, setting off a cultural exchange that would snowball into the global K-pop phenomenon we see today.

By the early nineties, Korean entertainment companies started putting together glossy pop acts of their own, inspired by the music that they heard in nightclubs catering to Black American soldiers.

And from the very start, they incorporated English lyrics to borrow the cool factor of those hip-hop and R&B songs.

(poppy music) ♪ East Coast ♪ - 1992's "Nan Arayo - I Know" by Seo Taiji and Boys, widely credited as the first K-pop hit, opens with a chant of "East Coast," possibly in reference to the new jack swing sound originated by New York City producers.

A linguist analyzing those early years of K-Pop noticed patterns in when and how English was used.

One purpose was ad-libs, those heys, woahs, and yuhs in pop and rap songs that fill empty space and keep the energy of the song high.

These ad-libs signaled a certain sophistication, that the singer keeps up with what's cool in culture around the world.

Another use was to make rhyme schemes work by ending a pair of lyrics with English words when their Korean translations wouldn't otherwise rhyme.

(vocalist singing in foreign language) ♪ Spot, spot, spotlight ♪ (vocalist singing in foreign language) ♪ I know it's not right ♪ ♪ I can't stop me, can't stop me, ooh woah woah ♪ - But the researcher noticed K-pop artists also used English to communicate new layers of meaning, specifically to native Korean speakers.

In these new pop songs, bold or risque lyrics were a departure from South Korea's more conservative cultural norms, and singing them in English only reinforced their edginess.

The mixing of language could also be symbolic.

A song about an unfaithful partner might switch back and forth between languages to evoke their double life, or an artist might sing in Korean about shyness around a crush, cutting in with their straightforward feelings in English.

(vocalist singing in foreign language) ♪ 'Cause I'm your girl, hold me baby ♪ - If English in early K-pop was being used to add meaning to other Koreans, that started to change as the advent of YouTube and streaming services started making the music accessible to more native English speakers.

♪ Gangnam Style ♪ - When Psy's quirky hit "Gangnam Style" became the first YouTube video to rack up a billion views, the global reach of K-pop exploded, and so did the genre's use of English.

Linguists who analyzed over a decade of top 50 K-pop hits found that in 1990, only 8% of these songs used English words in their title.

By 2012, 44% of them did.

Korean entertainment companies who hoped to expand their global reach had started introducing more English lyrics to attract international fans.

The strategy worked well for artists like BTS and Blackpink, who started appearing on US charts by the late 2010s.

It's also around this time that English lyrics in K-pop songs started to take on playful double meanings.

Take BTS's "Blood Sweat & Tears."

(vocalist singing in foreign language) - Or ITZY's "Dalla Dalla."

♪ I love myself ♪ (vocalist singing in foreign language) - While these lyrics translate literally to "I want more and more and more" and "I'm different," linguists note that the resemblance to the English words "Money" and "Dollar" placed them comfortably within the pop music convention of bragging about cash.

But mostly, Korean artists started incorporating more and more English to get more international airplay.

Despite topping Billboard album sales charts since 2018, boy band BTS didn't find a foothold on American radio stations until their 2020 song "Dynamite," their first single written entirely in English.

♪ This is gettin' heavy ♪ ♪ Can you hear the bass boom ♪ ♪ I'm ready ♪ - Since then, many K-pop artists have released fully English tracks, or in the cases of members of the girl group Blackpink, entire English albums.

These days, K-pop artists flow so freely between Korean and English lyricism that the genre isn't defined exclusively by the language it's sung in, so much as the artists who are singing it.

But don't worry too much about K-Pop losing its Korean language roots.

Linguists have noticed that the trend of language mixing is also starting to move in the other direction.

Universities are seeing an uptick in Korean language learners, fueled in large part by students' love of K-Pop and the desire to better understand their favorite songs.

The Modern Language Association found that enrollment in university-level Korean language classes rose 78% between 2009 and 2016.

And fans who watch their favorite artists' interviews and livestreams are helping to bring Korean loanwords into the English lexicon, like oppa for a male friend or love interest, or mukbang for a video stream where a host chats with the audience while eating a meal.

Recently, the movie "K-Pop: Demon Hunters" inverted K-pop conventions by selectively sprinkling Korean lyrics into songs written almost entirely in English.

So, borrowing Korean words and phrases for an international cool factor probably isn't far off for American pop.

It's true that English and Korean have been in close contact for at least 70 years, but the past few decades have seen so much intermixing between English and Korean, not because of physical or geographical closeness, but because of cultural proximity.

K-Pop's global rise is giving artists and fans a pop culture playground where they can do anything from experimenting with a few new loanwords to forging meaningful multicultural identities.

And in the meantime, we all get some fun new tracks for our playlists.