I'm looking for instances of "David" being used as a vocative. How do I do that? What I have is obviously wrong. (Thanks in advance for helping a new user!)
Use the @ to tag the lemma, just like Accordance, eg lemma.g:Δαυίδ@NV. In this particular example, David isn't declinable, so Logos doesn't have it tagged as such. Try addressee:David instead of a morph search.
Perfect! Thanks Jonathan!
For many of these types of questions, the secret is the right-click Context Menu.
You can copy the search argument as well to paste into more complex searches. You really need to become comfortable with the Context Menu to use Logos efficiently - it becomes your memory of how to do many things.