By now, you have likely heard the story of how director Alfonso Cuarón found the actor who would star in his epic and deeply personal film, Roma: a casting search led him to the Mexican state of Oaxaca, where he met schoolteacher Yalitza Aparicio. She had never acted before, much less in a movie. Yet she would go on to play Cleo, a housekeeper and nanny for a family living in Mexico City's Roma district. Playing opposite Aparicio is Marina de Tavira, whose Sra. Sofía must endure an absent husband and the demands of their four children. For both, the roles were a challenge, not least of all because the story of Roma is based in part on Cuarón's own childhood. As they explained in W's annual Best Performances issue, however, that personal link helped imbue the story and their performances with a sense of realism unlike any they've felt before. Here, they discuss the tricks Cuarón played to help his first-time actors find their motivations, their favorite music, and how it felt to bring Roma to the town Aparicio still calls home.

How did you become involved with Roma?

Yalitza Aparicio: A casting came to my hometown [Tlaxiaco, Oaxaca] and I went through various steps until I finally got to the test where I met Alfonso [Cuarón]. I was a little bit afraid, because I had never done [a movie]. But I was curious, and my sister actually forced me to audition, and then it became an adventure.

Marina de Tavira: I come from a family that has a strong theater tradition and I've worked in films and television in Mexico, but my work has been mostly on stage. I went through a very long casting process that lasted three months. At the end of that process, I learned that I had been auditioning for a film that was going to be directed by Alfonso Cuarón that was called Roma.

You did not know that until the end?

MdT: I did not know that. I did not know that I was auditioning for an Alfonso Cuarón film until the very day I met him.

Marina, you play the mother character in a film based on Cuarón's childhood. Did he tell you you reminded him of his mother?

MdT: He never said that I reminded him of his mother, but he said that he invited Yalitza and me together to be involved in a very, very personal film for him. He said it was about life, and if we had time to do it...

Yalitza, how long was the shoot?

YA: For me, it was a very long process. It lasted almost six months, and I just let all the people around me pull me through it in chronological order. First I thought it was a normal process, but it was actually a very long process for me.

Marina, did he shoot it in sequence? Or try?

MdT: Alfonso shot this film in absolute chronological order. We went from day one 'til the last day of the story.

What was filming like for you, Marina?

MdT: I was the only actor in Roma with any previous experience. It was really challenging. First-time actors—and many of them were children—have a completely different way of working. Alfonso would play tricks on us—make things happen that we were not expecting. That way, he made real life appear on set.

Had you ever driven that big a car?

MdT: [Laughs] No, never. I drove three different cars, and each one of them had very complex way of functioning. I don't think those cars can fit in Mexico City anymore.

Yalitza, what was your favorite part of playing the character?

YA: The thing I enjoyed the most was being on set. I really liked observing how everybody worked and learning about the process. It truly transported me into another world.

What kind of things did [Alfonso] throw at you that were surprising?

YA: I'm mostly impressed by his vision and the fact that we would be shooting a scene and he was so attentive to details that were completely imperceptible to me. He really is quite magnificent in the way that he does things.

Marina, was there an intensity about the fact that you knew it was autobiographical?

MdT: At the beginning, I felt a very intense responsibility to be portraying his life and his memories. But as we went through the process, these memories became our memories and we embraced the project as if it was our own life and, and connected with our own experiences.

Yalitza, have you seen any other Alfonso Cuarón films?

YA: I had not seen any of his films. I actually didn't know who he was. I was even a little bit embarrassed when I first met him, to tell him that no, in fact I didn't know who he was or what movies he had made. And he asked me, actually, not to watch any of his films. He didn't want me poisoning my mind with any images or ideas.

MdT: I’ve known Alfonso's work for quite a long time. I attended the Y Tu Mama Tambien premiere in Mexico. I was sitting in the movie theater, not imagining that one day I would work with him.

Yalitza, what was it like to watch the movie in Tlaxiaco?

YA: It was quite an incredible experience to see it with people from my community. A lot of people came up to me afterward and told me that they really saw themselves, and almost felt like it was them in the film living through those experiences.

And Marina, are you a music person?

MdT: I absolutely love music. It is the one thing that connects with you without processing it rationally. It just grabs you.

YA: I love music very much. In fact, I like music from the era that the film is made in. Mostly because it was the kind of music that my parents used to listen to at the house.

What was the first album you ever bought?

MdT: The first album I ever bought was a vinyl. And it was a little cricket that sings for children. I had a box with all the vinyls and I would just look at them back and forth for hours in my room.

Alfonso sometimes makes a little soundtrack for each person to sort of put them in the place of the movie. Did he do that for Roma?

MdT: Alfonso really wanted us to work with no external opinions from him. Just go really in a very personal journey. So I made my own soundtrack, and I was really surprised when I saw the film that many of the songs that I chose and that I was listening to while I was waiting to be on set are actually in the film, like “I Don’t Know How to Love Him” from Jesus Christ Superstar.

Yalitza, was there anything in particular that you learned when you made this movie?

YA: Actually, the thing that I learned was how to speak Mixtec, which is a language that I had grown up listening to, but I didn't actually know how to speak. Nancy, who plays Adela in the film, was actually my teacher.

And Marina, same question for you. Was there any particular thing that brought you to Sofía more closely?

MdT: Well, I had to learn how to drive a car where you change the gears. That scene where the car gets stuck between the two trucks was incredible because I kept going through perfectly. Alfonso kept putting [the trucks] closer and closer, because somehow I just got through them.