Fury still yearns to master basic grammar but on Saturday he steps back into the ring for the first time in 10 months

"All I really need to do is count," Tyson Fury says bluntly as our second interview in five months takes another twist down the strange path followed by the giant man who might end up as the world heavyweight champion this year. "I just need to count the rounds and count me money afterwards."

This is the dark Fury. This is the grim Fury on a rainy winter morning in Cannes. This is different to the more wistful Fury I met last September, on a beautiful autumnal afternoon in Essen, a small town in Belgium. Fury was then preparing for the biggest fight of his life against David Haye. In his final week of training before facing Haye, he sounded unusually reflective.

"I'm not an educated person with any proper schooling," Fury said last year outside the Swiss-style chalet that had been his home in Essen for eight long weeks. As sunlight streamed through the trees it seemed a poignant time for Fury to consider his life as a fighter and Traveller who had left school at the age of 10.

The wooden house belonged to his trainer and uncle, Peter, who had begun to educate himself during his second long spell in prison. Fury, however, regretted his failure to have learnt how to write properly. He might have seemed on the brink of earning over a million pounds against Haye but he smiled ruefully. "I'd like to take a course in writing. I'm not the best writer in the world. I'd like to write more neatly, even though people don't send many handwritten letters these days. It bothers me but it's hard when you're one of them people who don't know where to stop sentences or put commas or exclamation marks. You feel like an illiterate dummy, don't you?"

Fury's face creased with emotion as he said: "I can fight but that's the only thing I can do. When it comes to anything other than fighting, or talking, I'm not very good."

Yet his scatter-gun intelligence had been obvious during a long conversation in which he had wafted through subjects as diverse as depression and discipline, addiction and hope, religion and money – and his complicated feelings towards Haye. The fight, of course, was postponed and then cancelled by Haye and our interview never ran.

And so we are back again with Fury training hard in Cannes before, for the first time in 10 months, he fights on Saturday night. He was meant to meet Gonzalo Omar Basile – but last week the Argentinian also withdrew from their contest with a lung infection. Fury now faces the American Joey Abell at the Copper Box in London in his debut for Frank Warren's BoxNation channel. But his desire to improve his level of literacy has been dented.

"I'm not really interested in that at the minute," Fury says when I ask what happened to his yearning to master basic grammar. His stream of abusive and homophobic tweets to Haye, Lennox Lewis and Wladimir Klitschko would have had the Fury of Essen hanging his head in shame.

"@mrdavidhaye Is a fucking shit house cunt! …" is a pretty boring tweet. But Fury's grammar and punctuation is disappointingly sloppy in the heat of another tweet: "If @LennoxLewis has any balls left at all come fight me & ill have u carried out on a stretcher u fucking pussy! Come & try!!!"

There is no need to worry about Lewis's reaction, for the once great heavyweight champion is bright enough not to take Fury seriously, but I'm missing the boxer who spoke touchingly about the elusive art of the hard-written letter. "I'm just interested in winning the next few fights and making plenty of money," Fury says, putting up with my chiding. "Probably when I'm retired from boxing we might take some time out and do some advanced writing lessons. It could be good but at the moment I'm busy with my career."

After his stark plug for the benefits of numeracy ahead of literacy in the crude old fight game, Fury is again in a talkative mood. "I had a lottery win a few months ago and then it got taken away," he says of his lost Haye money-spinner. "You'd be upset, wouldn't you? It was like winning the lottery – being a week away from spending your money and then suddenly not having any of it any more. It's hard to adjust. At least Joey Abell's not like David Haye. Joey will come and take a beating … no doubt about that."

Fury reverts to simple addition as he counts the cost of the Haye cancellation. "I lost £150,000 in expenses. It also cost me my pay-per-view purse and a final IBF eliminator, so that was a few million more. It's sickening really but I'm only 25. It's not like I'm 42 and near the end of my career. I don't need David Haye and his antics to earn money.

"I was so fed up I retired for a few months but now I'm back with a vengeance. I've come back because I need the money. I can't get another job, so it looks like I've got to do this job for the rest of my life."

He sounds a little desolate but whether Fury is happy or sad, confused or elated, he always talks openly. And so we return to the homophobia that breaks out so often when he's angry. In October 2012 he blamed his cousins for posting spleen in his name on Twitter when he threatened his heavyweight rival David Price that he was going to put "you and gay lover Tony Bellew" in intensive care.

His cousins were not involved when, last October, he followed predictable tweets abusing Lewis and Wladimir Klitschko with homophobia. "I think @LennoxLewis & wlad @Klitschko r 100% Homosexuals!!"

Fury's father named him after Mike Tyson. And so I tell him how, in our interview last month, it was interesting hearing Tyson celebrate the layered life of Panama Al Brown – who, apart from becoming boxing's first Hispanic world champion in the 1920s, had a long affair with the gay French writer and film-maker Jean Cocteau. "I've never heard of him," Fury says of Brown.

Does Fury believe it's impossible for a gay man to be tough? "I don't know. If a man likes to mess around with another man it's his own business isn't it? But I'm an old-fashioned person. I'm a married man with kids. I'm not interested in all that stuff. I don't even want to go there."

So why does he seem to enjoy using homosexuality as a supposed insult on Twitter? "Look, I try to get myself big fights. You've got to get out there and so I try to lure them into taking a fight against me. I give them the bait. But Lennox don't want to fight no more, does he? The Boxing Board of Control gave me some fines but boys will be boys and I've got to speak my mind haven't I?

"I've been fined 17 grand – last time it was 10 grand, the time before that it was seven. It's just chucking money down the drain but I'm getting fined for speaking my mind. You can't be honest in this day and age but I'm going to keep being honest and keep getting into trouble."

Warren has announced his intention to match Fury against Dereck Chisora in the summer – probably at Upton Park – in another clash of two volatile heavyweights. Fury won their first encounter, on points over 12 rounds in July 2011, but Chisora has since became much more infamous for slapping Vitali Klitschko before their 2012 world title fight, in which he fought creditably between the ropes, and then for threatening to shoot Haye in the brawling aftermath.

Chisora has also bitten an opponent in the ring – and kissed another at the weigh-in. When Klitschko shook his head primly and said: "I'm very conservative. I only kiss women," Chisora drawled, "I swing both ways, player, I swing both ways. Don't worry about that."

It was the kind of provocative statement that might unsettle Fury. I also remind him that, when I interviewed him just before he fought Klitschko, Chisora said: "People are ignorant. Bisexuality started a long, long time ago. You just have to support it. There's nothing wrong with it. I support the gays 24/7."

Fury pauses. "If he wants to be a bisexual or whatever that's up to him really. He can be what he wants … as long as he don't interfere with me."

It is striking that Fury and Chisora, who can be such opposites amid their wild outbursts, should harbour mutual respect and even like each other.

"I get on well with him," Fury says of Chisora, who also fights on Saturday's bill. "We had a hard fight last time and there's no bad blood there. It's purely business. I've got this warm-up against Abell and then it'll be Chisora. After that I'll be the mandatory for a world title. That's when the real games begin. I'm a prizefighter fighting for a prize. All I'm interested in is money. I don't care about nothing else. I don't care about world titles or being a hero."

Fury recalls our first interview. "You came to see me in Morecambe," he chuckles. "I remember it well." In November 2011, Fury told me that he felt "sad, like commit-suicide-sad" and "messed up" before, looking around the front room where we sat with his wife, Paris, and their exotically named children Venezuela and Prince, he admitted that: "I really feel like smashing this place up."

Now, Fury says cheerfully that should he and Paris have another child, "I like the name Hunter for a boy. Hunter Fury? It's got a ring to it."

So how is his state of mind today when, every time I meet him, he always cuts such a contrasting figure? "The state of mind is good. I'm ready for a decent fight. Joey Abell's had 29 wins, 28 knockouts, seven losses. He boxed [the unbeaten] Kubrat Pulev last time out and Joey put him down, so it's a good little test for me. I have a nightmare every time I fight a southpaw like him, so it could be interesting."

This is a sensible way to sell a match-up against an anonymous journeyman. But the fight that Fury really wants is against Wladimir Klitschko. "I don't know whether he wants to fight me," Fury says. "I don't think anyone really believes, deep down, that they can beat me. It's a massive task fighting someone like me who is 6ft 9in and who trains really hard, who can box for 12 rounds at a fast pace. To think they can beat me? They're kidding themselves. But I'd love it to be Wlad. I'd talk up a storm for that one … "

Tyson Fury vs Joey Abell is live on BoxNation (Sky Ch.437/Virgin Ch.546) on Saturday 15 February. Visit www.boxnation.com