Translation: That's a linguistic question, not a mathematics one. In Portuguese there's a very small difference between "differentiable" and "derivable" (in t

Translation: That's a linguistic question, not a mathematics one. In Portuguese there's a very small difference between "differentiable" and "derivable" (in the context of Math Analysis), but I don't recall it. English being a mutable language, may end up absorbing the difference between nomenclatures in that way (??): derivable x differentiable.