| Present "understand" | I | understand | |
| Present Continuous "understand" | I | am understanding | |
| Simple past "understand" | I | understood | |
| Past Continuous "understand" | I | was understanding | |
| Present perfect "understand" | I | have understood | |
| Present perfect continuous "understand" | I | have been understanding | |
| Past perfect "understand" | I | had understood | |
| Past perfect continuous "understand" | I | had been understanding | |
| Future "understand" | I | will understand | |
| Future continuous "understand" | I | will be understanding | |
| Future perfect "understand" | I | will have understood | |
| Future perfect continuous "understand" | I | will have been understanding |