Which has a shallower depth of field?

Nikkor 50mm f/1.8g or 35mm f/1.8g?

The longer the lens, the shallower the depth of field a lens has at any give lens aperture.

The lens with the shallowest depth of field at f/1.8 would be the 85 mm f/1.8

A lens does not have an shallow depth of field inherently. One has to set it to have a shallow depth of field. One lens or the other might be CAPABLE of having a more shallow DoF but, for example, each of these lenses could provide a more shallow DoF than the other depending on how YOU set them.

The longer the lens the more shallow DoF it is capable of. But DoF is made shallow by focusing closer and opening the aperture wider. So therefore, the closer a lens can focus and the bigger the maximum aperture the more shallow a DoF it can produce.

I hope this helps you but you should also read a basic photography manual in order to learn this and many other photographic concepts!

Both at f/1.8 at the same distance to the subject? The longer focal length, 50mm will have shallower DOF.

The nikkor 50mm f1.8 try, DOF calcultor.

There's so much more to this than what you might think. You have to take into consideration also the distance between you and your subject and the distance between your subject and its background. All other things remaining the same, the 50mm would give you what you're looking for