When Howie Mandel played a Boston doctor on the 1980s medical drama St. Elsewhere it wasn't the medical jargon he struggled with — it was his Canadian accent.

"I can't tell you how many times they stopped filming on St. Elsewhere because I said 'intes-tyne' instead of 'intest-tin,' or I said 'dra-ma' instead of 'draw-ma,"' says the Toronto-born America's Got Talent judge.

"They just kicked the Canada out of me."

Over Canada's 150-year history, the Canuck English accent has varied in sound and strength, depending on the region. And it comes through more in certain words — like about, mouth, pasta, lava and avocado.

Howie Mandel remembers saying 'intes-tyne' instead of 'intest-tin,' as preferred when he played a doctor on the 1980s medical drama St. Elsewhere. (Peter Power/Canadian Press)

Though the accent can be subtle at times, it can be a hard one for some homegrown actors to shake when they're playing non-Canadian characters.

"You can't say 'drama' or 'pasta' or 'story,"' says Vancouver-born comedy star Seth Rogen, whose AMC series Preacher is into its second season.

Only a few words 'an issue'

"I consciously have to not talk like a Canadian, if I'm playing an American character. There are only four or five words for me that really have become an issue."

Big Little Lies star James Tupper of Dartmouth, N.S., says he "went home in tears" while trying to shake his spirited accent in drama school.

'I just didn't hear it and it took me forever, but I finally did learn the variations in my tongue and how to make an American sound, and I feel confident with it now.' - Actor James Tupper

"I just couldn't hear it," he says. "I would say, 'It's not very fa-her to the ca-her.' They would say, 'It's not very far to the car.' I just didn't hear it and it took me forever, but I finally did learn the variations in my tongue and how to make an American sound, and I feel confident with it now.

"But I'll tell you what — when I go home, the wild Nova Scotian that lives in me comes out. I have the thickest accent of any Nova Scotian you've ever imagined."

Big Little Lies star James Tupper says he's confident he can pass for an American, despite having 'the thickest accent of any Nova Scotian you've ever imagined.' (Jordan Strauss/Invision/AP)

Property Brothers star Drew Scott says he also worked hard to get rid of his accent while acting in his native Vancouver.

"One of the issues I had is a lot of U.S. shows coming to shoot there and they said, 'You're a great actor but I can still hear the Canadian-isms,' and I needed to not have that," says Scott.

Bee-n versus bin

"The funny words that you watch out for are 'tomorrow' which sounds like 'tah-more-oh,' or 'about,"' adds twin brother/co-star Jonathan. "The word 'been,' Americans say 'bin' but Canadians say 'bee-n."'

Still, some actors don't bother going through such great pains.

Toronto-raised Mike Myers, for instance, proudly injected his Canuck accent in his American Wayne's World character.

"Wayne has a Scarborough accent with a Canadian rise. I made no attempt to sound like he was from Chicago," says Myers, who has a section on the Canadian English accent in his book "Canada."

"(While acting) in England it was, 'Should I be American, should I be a limey?' And I was just like, 'Ah, just be Canadian."'

According to Charles Boberg, an associate professor of linguistics at McGill University, there are two main differences in Canadian English pronunciation of vowels.

'Canadian rising' with vowels

"One of them is called 'Canadian rising,' and this is the stereotype that most Americans have of Canadian English and it involves the 'OU' vowel sound and the 'I' vowel. It's referring to raising the pronunciation of the vowel in the mouth," says Boberg, author of The English Language in Canada.

"When we say 'raising' we mean that the tongue isn't as low for pronunciation of words like 'mouth' and 'price' for Canadians as it is for Americans."

Canadian raising, which Boberg says may have its origins in Scottish English, has stuck with Mandel: "I still don't hear the Canadian 'about' ... but I'm told that sometimes I say it — 'about,' or 'house,"' he says.

Then there's the "Canadian shift," which involves vowels moving around in the mouth, leading to subtle pronunciations like "drass" instead of "dress."

Shift on the letter 'a'

The Canadian English accent also comes through in words that hail from other languages and the main vowel sound is spelled with the letter "A."

"An example would be ... 'paw-sta' is the American pronunciation but 'pa-sta' is the Canadian pronunciation and really sounds weird to Americans," says Boberg.

Those on Canada's West and East Coasts pronounce words differently than those in the central provinces. On the West Coast, for instance, words like "out and about" are pronounced more like "oat and aboat," says Boberg.

Blending in easier for actors from B.C., Prairies

The western Canadian dialect is similar to that of California, making it easier for homegrown actors from British Columbia or the Prairies to blend in linguistically in Hollywood, he adds.

"What's funny is the hardest time I probably ever had doing (an accent) was when I was in Sarah Polley's (Canadian) movie (Take This Waltz)," says Rogen.

"In the West Coast, we don't say 'about' like how they do in the East Coast of Canada and I was supposed to be a guy from Toronto and I couldn't for the life of me say 'about' like a guy from Toronto does."