They sound the same to me. Can Americans and Canadians tell themselves apart based on the way they talk?
You can, but you have to listen closely.
Probably, the biggest thing is this: https://en.wikipedia.org/wiki/Canadian_raising
For me, it's easy to tell the difference between an American 'about' and a Canadian 'abaeut'
Canada is a big country.
Like bigger than Europe by a significant amount.
Someone from Manitoba, Vancouver, and Newfoundland will all sound very different from each other.
It's like comparing a Texan to a Bostonian, or someone from SoCal to someone from the Bronx.
Innernet = internet
awrenge = orange
sorry = sawry
soda = pop
sorry = soaree
If someone physically bumps into a Canadian on the street, the Canadian will always apologize "for being in the way".
Like other's have said, Canada is big, so there's no one singe accent. Western Canada basically has the default "American accent", eastern Canada has more distinct accents. For example, someone from ontario might pronounce car as "care", or might say aboot. The maritime province's accents are some kind of fucked up Scottish-influenced abomination.
Americans say mawfia and tawco, Canuckians say mahfia and tahco.
Both Canada and America have several different accents, many of which overlap between the two countries. You'll find people in Wisconsin and Minnesota, for example, who speak with what sounds like a stereotypical Canadian accent.
Most examples people are giving on here actually aren't very reliable.
There are quite a few American accents depending on where you go. Canada is the same. Some meld into the others. It can be difficult to differentiate. There tend to be some subtle differences, but sometimes there aren't.
Some people in Canada are going to be indistinguishable from people in New Hampsire, Vermont, Minnesota.
They typical "Canadian" stereotype is only the far, far east coast.
The easiest way is to see whether they use Metric and Celsius.