Martin Freeman revealed he 'spoke in scouse' for a year and a half in order to perfect the Liverpudlian accent.
The actor is starring in BBC's news drama The Responder.
The Responder follows Chris Carson (Martin Freeman), a crisis-stricken, morally compromised, unconventional urgent response officer tackling a series of night shifts on the beat in Liverpool.
READ MORE: Ex Merseyside Police officer on why he wrote The Responder
Whilst trying to keep his head above water both personally and professionally, Chris is forced to take on a new rookie partner Rachel (Adelayo Adedayo).
Both soon discover that survival in this high pressure, relentless, night-time world will depend on them either helping or destroying each other.
The show was created by ex-police officer Tony Schumacher, who worked for Merseyside Police.
In an attempt to understand his character, Martin went to great lengths to prepare for the role, including ‘speaking to himself in scouse’ for an entire year and a half.
Martin told Metro : "I didn’t watch anything [to take inspiration].
"I have spent a lot of time in Liverpool in my life.
"Talking to people in the city and talking to people and to Tony was part of it."
He added: "I walked around for a year and a half, occasionally just talking to myself in scouse. Even though you’re not always the best judge of your own thing, I do trust my ear.
"If I say something, I know when it sounds off. I got very, very exact about that stuff. You have to be because if I don’t do it well, it’s a terrible accent to get wrong.
"There are some accents where you don’t want to be in that city among the inhabitants of that city making a balls-up of it."
The Responder airs from Monday at 9pm on BBC One and on BBC iPlayer.
