A Short Grammar of Classical Greek: Mute Verbs

Dental stems drop their final consonants δ, τ, θ before σ and κ (see ἐλπίσω § 39.1), but change them to σ before μ or other dentals.

Note. σπένδω takes compensative lengthening throughout: σπένδω, σπείσω, ἔσπεισα, (ἔσπεικα), ἔσπεισμαι, ἐσπείσθην.

With suffix ‑σ‑:

• any guttural → ξ
• any labial → ψ.

Before μ:

• guttural → γ, labial → μ.

Before τ:

• guttural → κ, labial → π.

Before θ:

• guttural → χ, labial → φ.

These stems have no first perfect active in ‑κα; if they have any perfect active at all, it is the second (see § 88).

The final consonant of the stem is assimilated to the initial sound of the endings, and σ is dropped between two consonants. Only these combinations occur:

Endings ‑νται and ‑ντο cannot be added to consonant stems. Therefore 3rd plural is always formed by the perfect participle passive plus:

• εἰσί(ν) / neuter ἐστί(ν) in the perfect;
• ἦσαν / neuter ἦν in the pluperfect.

a) ψεύδω “deceive” (stem ψευδ‑)

(Здесь строка “ἔψευσταί” — обычное 3 sg perf. mid. ἔψευσται; я разделил по колонкам, но не менял морфологию.)

b) πράττω “do” (stem πρᾱγ‑)

c) γράφω “write” (stem γρᾰφ‑)

- στρέφω turn, τρέπω turn, τρέφω nourish change stem vowel ε → ᾰ in perf. mid./pass.: ἔστραμμαι, τέτραμμαι, τέθραμμαι (§ 21.2).

• Consonant clusters are avoided: πέπεμμαι, πεπεμμένος (not πέπεμμ‑μαι, πεπεμμ‑μένος) from πέμπω, etc.