Naming compounds

Question

SF(sub)2

would if be just sulfur fluoride

same goes with SF (sub)6

Sulfur Fluoride?

Answer 1

sulfur(II) fluoride or sulfur difluoride.
sulfur(VI) fluoride or sulfur hexafluoride.

Answer 2

What if it's Li(sub)3 N
would it be....
trilithium nitride? no?
Lithium nitride?

Is there a website on rules for naming compounds?

Answer 3

I think either would be correct. I call it lithium nitride. Since lithium has ONLY the +1 oxidation state, it isn't necessary to denote that (as in lithium(I) nitride) and I don't think it's necessary to say trilithium for the same reason.