"Do they also speak French in Canada?"
Translation:Est-ce qu'ils parlent aussi français au Canada ?
"Au Canada", because "le Canada" is a masculine country; "en France", because "la France" is a feminine country.
For the latter interpretation, I would place "aussi" after Canada.
With "aussi" after "parler" or after "français", context would be necessary to settle the real meaning.
In theory, though, "aussi" should be placed after the noun it is supposed to modify if you expect to be properly understood:
- Au Canada, les gens (écrivent et) parlent aussi le français.
- Au Canada, les gens (parlent anglais et) parlent le français aussi.