Thematic Infinitive Progressive Middle and Passive
Introduction
The thematic middle (and passive) infinitive marker is /εσθαι, where -ε- is a theme vowel. This is added to the progressive stem to create the thematic middle and passive progressive infinitive:
ἄγ/εσθαι > ἄγεσθαι
γι/γέν/εσθαι > γίγνεσθαι
τέμ/ν/εσθαι > τέμνεσθαι
| BASE | progressive aspect marker(s) | /εσθαι |