CUM + Indicative = When (present, future) When/While (Perfect, Imperfect, Pluperfect)
CUM + Subjunctive = Since/Because,
Although (often includes tamen)
CUM TEMPORAL CLAUSE ( ***= when)
If the main verb is Primary (Present, Future, Future Perfect) and relates to present or future time,
*** takes the Indicative mood. This type of clause most often describes precise time.
Cum doceo vos, felix sum
When I am teaching you all, I am happy.
CUM CIRCUMSTANTIAL CLAUSE (*** = when, while)
If the main verb is Secondary (Imperfect, Perfect, Pluperfect), relates to past…