[capt_noonie]

Sometimes yorkies and silkies can look like each other, but if they are truly bred to the standard, it is easy to tell the difference. Silkies have a more slanted triangular head and larger muzzle as opposed to yorkies more rounder and smaller muzzle, which I think is the easiest way to tell them apart. You can read up on their standard on the AKC site.

but again, just like people, we all vary in looks. For instance, a human's "breed" (ethnicity) not all of the same ethnicity all look all the same. Same with dogs.

The only way to be sure is a dna test.