Do not be embarrassed to ask this thing! I probably know less about linguistics than you do. When I write Doctor Who fic I do that thing that the show-writers also do: I slap about some appropriate-sounding bits of technobabble and hope that the audience does not go "Hang on, that doesn't make much sense" or at least that they go "Well, that doesn't make much sense but at least it makes more sense than the Adipose/Cassandra/the one time Five defied the laws of physics using only a cricket ball". All this said, yeah, it probably is a possible/actual distinction than a past/present/future distinction. I can handwave this by saying that Gallifreyan understanding of time makes it the second sort of distinction? Dunno.

I should like a writing genealogy of my fic also! Um what the heck would it entail?