The midfielder arrived at West Ham under Manuel Pellegrini almost two years ago, but has found his feet during David Moyes's tenure and certainly knows how to handle himself in the Premier League now as the Hammers chase a remarkable European finish.
After defeat to Manchester City last month, the 25-year-old was given a ticking off for using some rather colourful language in an interview with international TV. Fornals apologised, explaining with a laugh that he had been learning cockney. He's not just wanted to add an edge on the pitch.
"When I arrived it was something interesting for me to discover and I’ve tried to learn some," Fornals tells Standard Sport. "I think if I have any trouble people can work out that I’m a cockney boy!
"The guys aren’t quite teaching me but these are the things that I am always listening to. On the pitch, here with the guys we have a lot of people who work in the club who are from London so it is the way they speak, it is the things I listen to. I know some cockney or east London, obviously I’ve got some rhyming slang, 'apples and pears' and things like that."
I am a team worker. I don’t want to be a West Ham superstar.
While Tomas Soucek, Declan Rice and Michail Antonio are taking all the plaudits in West Ham's rise, Fornals has quietly become one of Moyes's most trusted players, embodying the mentality the Scot wants from his squad.
Out have gone the likes of Felipe Anderson and Sebastien Haller with a focus on those ready to work.
"Football is a game of 11 players every game," says Fornals, speaking via Zoom from the club's Rush Green training ground. "I am a team worker. I don’t want to be a West Ham superstar, not defending and just playing one-vs-one with everyone all the time. I want to win and try to learn. My childhood I had to work and try to create a good atmosphere to win games so this is what I am trying to do."
That mentality was forged in a childhood spent playing football on the streets as Fornals grew up in the mountains just outside Castellon, playing day and night with little distraction or concern.
"I went to school in the city and my grandparents were in charge of taking me to school and picking me up," says Fornals.
"I used to be back in the mountains to play with my friends in the afternoon or at the weekends. I was lucky to grow up in a moment where the internet was growing up but it wasn’t the main thing like it is now.
"To be happy and do something I had to be on the street and of course in the mountains you don’t have the danger of many cars or things happening. My parents were quite easy to let me go in the street for a long time."
Fornals could not watch much Premier League football during his youth, but idolised the likes of Fernando Torres, David Silva and Santi Cazorla who moved from Spain to England and dreamed of following in their footsteps.
Before doing exactly that, the midfielder spent a season alongside Cazorla at Villarreal after the former Arsenal man's return from injury. An experience which left quite the mark.
"Santi is one of the people who probably could be good, could be bad but is always with a smile on his face," says Fornals. "This is a great thing to watch. Two years without playing football from injuries, big surgeries, a skin graft and doctors saying you’ll never play again. To return as he did, playing so well and being important for our club and the area. You can only say good things about Santi Cazorla."
His parents are still there in the mountains and, given their location, had not had a good enough wifi connection to be able to watch their son in a West Ham shirt until January 1 this year, when they beat Everton to begin a six game winning run and spark their unlikely Champions League push.
"They picked a good year," Fornals, who bought his parents a new TV to mark the occasions, says with a smile.
"After Christmas we were a couple of Hammers more. I’ve been here a year and a half and the first game they saw was against Everton. I am really happy that my parents can see our games and be involved a little bit more in what I’m doing or how I’m playing."
Having missed the relegation battles of recent years, expectations of West Ham will be high in the Fornals household back home.
Results last week saw the Hammers slip out of the top four but their fate is very much in their own hands ahead of the visit of Leeds United tonight and - with two years of experience in the Europa League with Villarreal - Fornals can only hope to be back there next season.
"After last week, as players and fans we were watching all the games to see how the results went but I think it means that while we are winning it doesn’t matter how the rest of the teams are doing. It is in our hands.
"It would be amazing [to play in Europe]. It is a dream, nothing compares to playing in Europe or the Champions League, you take your team to another level.
"It is good for the club and individually. Here there are players who have never played in Europe and it is one of the best things you can play as a footballer."