Roald Dahl's daughter Lucy: 'The first time I saw BFG I cried and cried and cried. I felt like I had spent two hours with my father'
Mark Rylance has admitted he often struggles with language and makes up "gobblefunk" words - just like his character, the BFG.
Despite his background in Shakespearian theatre, Rylance said he has a lot in common with the 24-foot-tall word-mangling Big Friendly Giant, whose linguistic inventions include "human beans", "whizzpopper" and "squiff-squiddled".
Speaking at the film's premiere in London's Leicester Square, the 56-year-old actor said: "I'm often confused and I've had a lot of difficulty with language in my life."
He told the Press Association: "As I get older I do find I'm making up words, because I forget what the right word is, and I often say the wrong word."
Steven Spielberg's version of Roald Dahl's 1982 novel sees Rylance as the kind-hearted BFG, who kidnaps young Sophie (Ruby Barnhill) from an orphanage and takes her back to his home in Giant Country.
Unfortunately, Giant Country is home to much bigger and nastier creatures.
Sophie and the BFG team up on an unlikely adventure which even takes them to Buckingham Palace, where they meet the Queen (Penelope Wilton) and try to enlist her help against the "cannybully" and "murderful" giants.
Rylance said Spielberg had been worried that too many "gobblefunk" words could confuse American audiences.
He said: " Melissa (Mathison), who wrote it, and I were always bringing more gobblefunk words to the set.
"Steven and the producers were a little nervous about whether the Americans would understand. But I'd say: 'Once you hear me say it in a sentence, you'll understand the word, even though it doesn't have any logical sense.'"
Barnhill, 12, said she could also see similarities between her co-star and his character.
She said: "Mark Rylance and the BFG are both such gentle and lovely people, and that's the main similarity I see whenever I watch the film."
The two stars were joined on the red carpet by Spielberg and actors Wilton, Rebecca Hall, and Rafe Spall, as well as famous faces including Sir Ben Kingsley and Great British Bake Off judge Mary Berry.
Dahl's daughter Lucy Dahl said her father would have been "delighted" with the adaptation of his children's book, which she has seen three times already.
Ms Dahl, 50, said: "The first time I saw it I cried and cried and cried. I felt like I had spent two hours with my father."
Dahl died in 1990, but his daughter said: " He would be delighted. Steven has done such a remarkable job, so has Mark, so has Ruby... everybody has really put their heart and their soul and their love and their compassion of the underdog as a child."
Downton Abbey actress Wilton said working with Spielberg was "a great thrill".
She continued: "I t's one of the things you dream of doing is filming with Steven Spielberg, one of the greatest filmmakers of the late 20th, early 21st century. And he's a beautiful storyteller who understands children's minds.
"Marry that with Roald Dahl, who's equally a great storyteller, you have a recipe for a great movie."
:: The BFG will be released in UK cinemas on July 22.