TORONTO — He's won two Tony Awards and has acted for at least four decades, but Brian Dennehy says he sometimes feels like "a punch-drunk amateur" when onstage at the Stratford Shakespeare Festival.

"It's one of those experiences for me where I have to be careful when I'm onstage because I have a tendency to stand there, gape-mouthed ... saying: 'My God, that's amazing -- look what that person is doing,' and I've got to get my mind back into the play," the American theatre, film and TV star said in a recent interview.

Dennehy -- who won best actor Tonys for his roles in "Long Day's Journey Into Night" in 2003 and "Death of a Salesman" in 1999 -- is starring in two shows at this year's Stratford festival: "Twelfth Night," opening Friday, and "The Homecoming," opening Aug. 11.

This is his second time performing at Stratford. In 2008, he was in festival productions of "All's Well That Ends Well" and the double bill of "Krapp's Last Tape" and "Hughie."

He hopes to continue returning, for many reasons, he said.

For one thing, the stage is a good fit for his life right now.

"I'm not in the movie business anymore, and hardly any 70 year olds are," said Dennehy, 73, who won a Golden Globe for his leading role in the 2000 made-for-TV movie "Death of a Salesman." His other memorable film credits include "First Blood," "Silverado" and "Cocoon."

"I always ask the producers: 'Are there no 70-year-old vampires?"' he added with a laugh. "Apparently there are not -- or even zombies for that matter. I guess they all get eaten."

Then there's Dennehy's aforementioned love for the Stratford festival, which he's been visiting from his home in Woodstock, Conn., for many years.

"It is ... the best theatre company in the world. I don't think there's any question about that, and I've worked everywhere," he said by phone from the quaint city in southwestern Ontario.

"I'm glad to slip in the back door and try to stumble around just so I can see these people. I'm not just saying it. It's the way I feel about it."

In "Twelfth Night" at the Festival Theatre, Dennehy plays Sir Toby Belch, the drunken and scheming uncle to Countess Olivia (Sara Topham), who is in mourning over the death of her brother.

Andrea Runge and Trent Pardy play twins Viola and Sebastian, whose separation during a shipwreck sets off a whirlwind of hilarious romantic misadventures and identity mishaps in the carnival-like setting of Illyria.

Co-stars include Stephen Ouimette as Sir Andrew Aguecheek; Tom Rooney as Malvolio; Ben Carlson as Feste; Cara Ricketts as Maria; and Mike Shara as Orsino, Duke of Illyria.

Dennehy said while he feels he's put forth some fine acting performances over the years, he hasn't done a lot of Shakespeare and doesn't feel he has "the fluency at it" yet.

His "Twelfth Night" co-stars, he said, "are far and away superior" to him onstage.

"Of course, they've worked in this language and in this period a lot longer than I have, but still, they're extraordinary actors, it's an extraordinary company -- and the musicians, the choreography, the singing," continued Dennehy, who's landed multiple Emmy nominations throughout his career.

"It's not just me. Friends of mine come up from New York and, in effect, they're saying to me: 'What are you doing out there?'

"But I'm scurrying as fast as my ancient legs allow ... and every once in a while something good happens."

Des McAnuff, the festival's Tony-winning artistic director, is helming "Twelfth Night" and co-composed the music for it with Michael Roth.

The actors play the instruments and sing the tunes throughout the production, which has a massive, elaborate set that resembles a broken mirror.

The production also has some contemporary costumes and some eye-popping props that highlight the magical, celebratory nature of Illyria and cultural changes happening in the Elizabethan era.

"It's a great ride," said Dennehy, who starred with Christopher Plummer in the 2007 Broadway production of "Inherit the Wind."

"(McAnuff) is an amazing, creative guy and it's a fun experience."