How do actors like Daniel Kaluuya and Daisy Edgar-Jones master new accents?

“It’s basically accent therapy,” says Audrey LeCrone, describing her job over Zoom. LeCrone is a dialect coach based in New Orleans who specialises in teaching non-American actors an American accent. Even for performers who clearly have a flair for the American accent, like Daniel Kaluuya – with whom LeCrone recently worked on Judas and the Black Messiah – a coach is vital.

“There’s still going to be certain rhythms or pitch patterns that are strange and that have to be monitored,” LeCrone says. This is particularly true when you’re playing, as Kaluuya is, a notable historical figure as voluble as the Black Panther leader Fred Hampton, who was killed by the FBI at the age of 21.

Dialect coaches are on hand for when the fatigue of filming creeps in. “When you’re on set and you’re shooting 12 hours a day, you’re going to slip up. I’m [Kaluuya’s] ears on set so he can focus on acting and I can catch him whenever he sounds a little British.” What happens if something slips through that net? “I tell the script supervisor or director that they’re going to have to do ADR [additional dialogue recording, when the actor’s speech is re-recorded after filming]. And then I hope and pray that they do it.”

If ADR doesn’t, or can’t, solve the problem, accents can fall into the realm of pastiche, as happened with the Irish accents in the recent romance Wild Mountain Thyme, starring Emily Blunt, Jon Hamm and Christopher Walken, and the often lampooned Far and Away (1992), starring Nicole Kidman and Tom Cruise.

To make sure his character’s accent was beyond reproach, Kaluuya spent months preparing his voice for Judas and the Black Messiah – he even took up smoking to add texture to it. An activist and master orator, Hampton was a man whose rhetoric was urgent, lyrical and had an unmistakable cadence, so it was essential to get it right.

“[Hampton’s voice] was oftentimes very fast and hard to understand,” LeCrone says. To help figure out exactly how he constructed sentences and to create a rhythm with Kaluuya that could work on screen, LeCrone slowed down archival footage of the Panther leader speaking. She also made Kaluuya take opera lessons. “Hampton’s voice was booming and present and big,” she says. “I knew the benefit of learning all that breath work and learning how to really get your voice out there.”

Part of the role of a dialect coach is figuring out how to actually teach an accent. “Just because I can do it, doesn’t always help me teach it,” says Jill McCullough, a British dialect coach whose credits include Billy Elliot (2000), The Iron Lady (2011) and the forthcoming No Time to Die and The Batman.

“How are you?” McCullough isn’t asking. She’s slipped effortlessly into a Northern Irish accent. To accomplish the ‘you’ sound, she describes her “tongue going high and close to her teeth”. You have to create a teaching system, otherwise “it’s just a girl in a room showing off”.

“Say I was going to teach you a Birmingham Punjabi accent. Right now, you’re unconsciously incompetent,” says McCullough. “You’ve got no idea that you don’t know how to do it.

“Once I start to teach you how to do it, you become consciously incompetent – sadly. Then you move round the cycle until the actor is consciously competent. They can do it, but they have to think about it.”

The ideal, of course, is to be unconsciously competent; to no longer be thinking about the mechanics and tongue movements. “It’s rare you get there,” McCullough admits.

McCullough likens the dialect coach to being a ‘no’ person, when everyone else surrounding the actor is a ‘yes-man’. Quoting Mike Myers, with whom she worked on Austin Powers: The Spy Who Shagged Me (1999), she says, “They’re the only person that ever tells an actor they’re wrong.” Ultimately, she says, it’s about reassuring an actor that she’s “not going to interfere with their process”.

Poll Moussoulides, a Dublin-based dialect coach, takes a slightly different approach. “By the time you get to principal photography, [the actor should be] ready to go. I much prefer that than being with them all the way through filming.” He senses that his presence could act as a distraction and in trusting that his actors are prepared, they will worry less about their dialect delivery.

Moussoulides had up to four months to polish British actress Daisy Edgar-Jones’s middle-class Sligo accent for her role as Marianne in the recent television adaptation of Sally Rooney’s Normal People.

“The biggest error people make with an Irish accent is that they put too much air into it.” Moussoulides demonstrates by pumping up his voice. “Suddenly it sounds like I really am a leprechaun.”

Yet part of all the preparation is about letting go of a hunger for perfection. “I think it’s better to be 85 per cent accurate, 100 per cent of the time, than 100 per cent accurate 30 per cent of the time,” Moussoulides says.

Similarly McCullough describes her approach as “character-based”. She operates on the belief that the depth and shade of a performance – not the accent – is king. Immersion trumps precision.