True or false: In the television show Friends, Monica Geller was invited to Rachel Green's wedding.
The question is part of an English lesson for international students in San Jose, California, that is based entirely on the show's pilot episode. It was designed by Ms Elif Konus, a teacher from Turkey who once binge-watched Friends to improve her own English.
The class, and the teacher's television habits, illustrate an international phenomenon that emerged in the 1990s and has endured across generations: Young people who are not native English speakers appear to enjoy learning the language with help from the hit sitcom that ran from 1994 to 2004.
Seventeen years after the final Friends episode, students and educators say the show, still seen widely in syndication around the world, works well as a learning resource. The dad jeans and cordless telephones may look dated, but the plot twists - falling in love, starting a career and other seminal moments in a young person's life - are still highly relatable.
"It's really entertaining compared with other sitcoms and it addresses universal issues," said Ms Konus, 29.
Over the years, several prominent celebrities have said they learnt English from Friends.
The list includes Jurgen Klopp, the German coach who helms Liverpool in the English Premier League; a number of Major League Baseball players whose first language is Spanish; and Kim Nam-joon, leader of the South Korean pop group BTS.
"I thought I was kind of like a victim at that time, but right now, I'm the lucky one, thanks to my mother," Kim, who performs under the stage name RM, told television host Ellen DeGeneres in 2017. "She bought all the seasons."
The Friends reunion episode that premiered recently on HBO Max included a cameo by the members of BTS and scenes from the show that had been translated into French, Japanese and Spanish. Fans around the world, from Ghana to Mexico, also reminisced about how the show helped them cope with personal dilemmas or tragedies.
Measuring the popularity of Friends as a teaching resource is an inexact science because so many people watch it outside of formal classrooms. But educators, academic studies and page-view data suggest that the show still has a wide following among English-language learners.
"I've been on YouTube for 13 years and I have not been posting Friends' content the whole time," said Ms Rachel Smith, founder of the learning site Rachel's English, based in Philadelphia. "But I've definitely never sensed that the time for it has passed."
In one apparent sign of that, Friends-based learning videos she posted in 2019 have received significantly more views a day on average - 839 - than those featuring other shows or movies, she said. After the United States, the most popular markets for her videos as a whole are Vietnam, India, Brazil, Japan, the Philippines and South Korea.
Other seminal American TV shows can serve a similar learning function, Ms Smith said, but they tend to be too particular for non-native English speakers. The humour in Seinfeld is a bit too gritty and New York-specific, for example.
"Other shows do work," she said. "Friends just seems to have the magic something that is even more attractive."
Fans and educators on three continents echo the sentiment, saying that Friends is a near-perfect amalgam of easy-to-understand English and real-life scenarios.
Ms Jamie Ouyang, 30, discovered the show during her last year of high school in south-central China when she bought a box set in her Changsha home town. She was hooked from the first episode, in which Rachel, played by Jennifer Aniston, meets the other characters in a wedding dress after abandoning her groom at the altar.
Ms Ouyang, who attended college in Ohio and now works as a film producer in Beijing, said Friends gave her the confidence to make small talk with Americans.
Friends may have endured as a teaching tool in part because the Internet has made it accessible to new generations of fans.
Another reason, said Professor Angela Larrea Espinar of the department of English studies at the University of Cordoba in Spain, is that people who teach foreign languages have gradually shifted over the last two decades from a "communicative" approach that emphasises grammar to one that encourages cross-cultural understanding and reflection. "Culture is a difficult thing to teach and, if you rely on textbooks, what you get is stereotypes," she said.
To avoid the textbook trap, Ms Konus built lesson plans around the sitcom's 1994 pilot episode.
In addition to the question about whether Monica, played by Courteney Cox, was invited to Rachel's wedding (answer: false), there are exercises that ask students to analyse scenes, idioms and character motivations.
After one class, a Turkish student observed that her teacher's English sounded not quite native, but also "not Turkish". Ms Konus said she took the comment as high praise.
How, the student asked, could one hope to reach the same level of English proficiency?
"Just watch Friends and try to imitate the characters," Ms Konus told her. "You'll get there."