pster wrote:2) And with a verb like ἥδομαι, ἡσθήσομαι, ἥσθην, it seems like you really need to know more than the principal parts to conjugate it, for example, to know that the aorist passive subjunctive retains the eta at the beginning. Comments? observations?
What would the eta become? If there's an eta in the present form, it's not going to go anywhere in non-indicative aorists or perfects. Take a look at ἡγέομαι, for example.
But in general, the "principal parts" formulation for Greek falls flat on its face quite a lot. Staring closely at a good, unabridged dictionary is going to be your safest guide, with the verb appendix in Smyth or a work like Veitch's Greek Verbs: Irregular and Defective
useful supplementation when gazing at the fine print in the LSJ makes you go cross-eyed.