How to form the aorist passive (and future passive):
1) First form the base, from present stem stripping away present markers (the same sort of ‘infices’ lost in 2nd aorist actives, ¨
like ἔ-λαβ-ον from λα-μ-β-αν-ω, losing the present infices, μ-αν
2) Add that base to the passive marker –θη-,
a) Stops to go their corresponding aspirate or –s-;
stops (voiced or voiceless) ---> aspirate or –s- before θ
labial |
β or π ---> |
φ |
velar (back) |
γ or κ ----> |
χ |
dental |
δ/ζ or τ -----> |
σ |
and often the vowel lengthens, λαβ --> ἐ-λήφ-θη-ν
b) vowel-stems lengthen (as in aor.act.): φιλέ-ω --> ἐ-φιλή-θη-ν
3) Then add past endings for aorist --- -ν, -ς, -- , -μεν, -τε, -σαν
For future (of course, no augment) add -σο- plus middle endings:
-σο-μαι, -σει, -σεται, -σομεθα, κτλ.
4) Give up figuring it out and just learn principle parts.