Logan Kearsley wrote:
> English typically relies on definiteness in a predicate nominal:
> "He is a doctor." (Proper Inclusion- he is a member of the category of
> "doctors".)
> "He is the doctor." (Equation- he and the doctor are the same person.)
> And indeed, equation can be seen as a special case of proper inclusion
> where the class in which membership is being asserted has cardinality
> 1. But in languages without grammaticalized definiteness, or with
> different conventions for how definiteness is defined, that specific
> approach won't work.
> So, do you worry about distinguishing those cases, and if so, how do you do it?

Some of my languages have different verbs for these cases, e.g. Jarda:

jö "to be" (member of category)
Jö tôṛ.
"He is a doctor"

Jöfa ķa tôs ğaś prêl.
"Love is an open door"

lê "to be" (the same)
Lê tôṛ.
"He is the doctor"

Lê lô xṛil ķa jenaj ķödê ravag.
"Only you are the life among the dead"