A tense formative is an affix that indicates a change in tense. The tense formative in English is the suffix -ed as in I walk (present tense) and I walked (past tense). In Greek, the tense formative is an infix as the κα in λελυκαμεν is a tense formative indicating the perfect tense. Other tense formatives in Greek are (the more common are bolded):
| Tense/Voice | Marker | Notes |
|---|---|---|
| Future Active | σ | |
| Liquid Future Active | εσ | Used for liquid verbs (λ, μ, ν, ρ); BBG 20.11 |
| First Aorist Active | σα | |
| First Aorist Active Liquid | α | Used for liquid verbs instead of -σα- (e.g., ἔμεινα, “I remained”). |
| Aorist Passive | θη | |
| Future Passive | θησ | |
| Perfect Active | κα | as in λέλυκα “I have loosed” |
| Second Perfect Active | α | e.g., γέγραφα BBG 25.14 |
| Perfect Active Participle | κ |