[*] 768. εἰμί (ἐσ-, cp. Lat. es-se) am has only the present and future systems.
| PRESENT | IMPERFECT | |||
| Indicative | Subjunctive | Optative | Imperative | Indicative |
| Sing. 1 εἰμί | ὦ | εἴην | ἦ or ἦν | |
| 2 εἶ | ᾖς | εἴης | ἴσθι | ἦσθα |
| 3 ἐστί | ᾖ | εἴη | ἔστω | ἦν |
| Dual 2 ἐστόν | ἦτον | εἴητον or εἶτον | ἔστον | ἤστον |
| 3 ἐστόν | ἦτον | εἰήτην or εἴτην | ἔστων | ἤστην |
| Plur. 1 ἐσμέν | ὦμεν | εἴημεν or εἶμεν | ἦμεν | |
| 2 ἐστέ | ἦτε | εἴητε or εἶτε | ἔστε | ἦτε or ἦστε (rare) |
| 3 εἰσί | ὦσι | εἴησαν or εἶεν | ἔστων | ἦσαν |