Augment, Reduplication, and Sound Changes

Augment

Type	Pattern	Example
Syllabic augment	ἐ- before consonant	λύω -> ἔλυον
Temporal augment	initial vowel lengthens	ἀκούω -> ἤκουον (common pattern)
Where used	past tenses of indicative	imperfect, aorist, pluperfect

Reduplication

Type	Pattern	Example
Regular consonant	initial consonant + ε	λύω -> λέλυκα
Aspirate	reduplicate with unaspirated mate	θύω -> τέθυκα (pattern)
Vowel initial	often lengthening instead	varies by verb

Movable ν and sigma changes

• Movable ν often appears in 3rd singular / 3rd plural forms before a vowel or pause: ἐστί(ν), λύουσι(ν), ἔλυσε(ν).
• Labial + σ -> ψ; velar + σ -> ξ; dental + σ -> σ (the dental disappears). These sound changes help explain futures and aorists.
• A final stem consonant may change or disappear before third-declension endings; this is why the genitive singular is essential for finding the stem.