How do you know you’re seeing a raven, not a crow? When they’re side by side the obvious difference is that the Common Raven is a lot larger (beak to tail 24,” wingspan 53," mass 2.6 lb. vs. 16,” 34,” 13 oz. in Northwestern Crow -- values from D. A. Sibley Field Guide to the Birds of Western North America).
The Raven also has shaggy throat feathers, a somewhat “Roman-nosed" bill, and the crown of the head is more high-domed.
In flight, the wings of the Common Raven are proportionally longer and narrower than in the crow, and the shape of the tail is distinctly different. It is diamond-shaped, the posterior margin forming a wedge, whereas the tail of the crow has a gently rounded posterior margin.
And another thing: it is usually the crow chasing the raven, which seems never to end. It must be tiresome being a Common Raven in the world of the much more common Northwestern Crow.