I’m working with Hansen & Quinn (Greek: An Intensive Course) in a course but often refer to Keller & Russel (Learn to Read Greek). I’m just to Lesson 41 in H&Q on Conditional Sentences and find a few disparities from K&D Lesson 96, for examples:
H&Q: Future Most Vivid: Protasis: ἐάν + Subj (does), Apodosis: Fut Ind (will do)
K&R: Future More Vivid: Protasis: εἰ + Φθτ Ινδ (does), Apodosis: Fut Ind (will do)
It’s just a slight difference in classification.
Future conditions are normally as in H&Q, but occasionally you find fut.indic used in the if-clause as well as the main clause.
And the difference between εαν+subj and ει+indic is the difference between “if X happens” and “if X is happening.”
There’s really nothing special about conditional clauses. They behave just like relative clauses and temporal clauses.
The H&Q Syntax Appendix has 9 categories of Conditionals vs just the 6 in the main text, with more of the degrees apparent.
Future Vivid appears to have Less, More and Most variations. Who may have, might have or will have thunck it!
As a retired (Bio)Chemist, I find Ancient Greek to be quite similar to my former field, in that the chemistry formulas one can learn are so straightforward compared to chemical reactions “in the wild”.