Canadians sometimes speak a bit funny. Americans think we say “aboot” instead of “about,” for example, because of something called a raised Canadian vowel.

It’s this type of subtle idiosyncrasy in our speech that leads one linguistics professor to believe an Islamic State militant -- one seen executing Syrian soldiers on video --  is from Canada.

At one point during an hour-long ISIS propaganda video released last month, a man is shown speaking in both Arabic and English as he brags about making Syrian soldiers dig their own graves.

Apart from his eyes, the man has his face completely covered. But as he threatens the camera, there’s one thing he can’t hide – his accent.

“There are certain clues in the words he uses that suggest he has at least some kind of Canadian exposure,” says Jack Chambers, a linguistics professor from the University of Toronto.

When the jihadist points to a pock-marked building and talks about the “bullet holes and artillery shells from the Islamic State,” Chambers says the man pronounces “Islamic” the way 75 per cent of Canadians do.

And when he says he’s “outside” the city of Ar-Raqqah, he says it with that raised Canadian vowel.

Darren Flynn, another linguist from the University of Calgary, agrees the accent is North American. And though he isn’t certain the speech patterns are specifically Canadian, Flynn says the way the man speaks reveals a lot about him.

“You can tell that he's definitely not working class,” he says. “He's from the north. He could be either on this side of the border or the American side.”

The FBI has released a clip of the video asking for information from anyone who might know the man’s identity.

It’s a search that Canadians should be taking seriously, says Lorne Dawson, a University of Waterloo professor whose areas of study include religion and radicalization.

“We don’t have the same attitudes as people in England, Denmark, the Netherlands and even the United States in terms of being prepared,” Dawson told CTV News.

“We haven’t had many incidents in Canada – terrorist incidents – but there’s a kind of rising tide of this activity, and I think it’s just a matter of time before something regrettable happens here.”

With a report from CTV News’ Laurie Graham