| Present "fathom" | I | fathom | |
| Present Continuous "fathom" | I | am fathoming | |
| Simple past "fathom" | I | fathomed | |
| Past Continuous "fathom" | I | was fathoming | |
| Present perfect "fathom" | I | have fathomed | |
| Present perfect continuous "fathom" | I | have been fathoming | |
| Past perfect "fathom" | I | had fathomed | |
| Past perfect continuous "fathom" | I | had been fathoming | |
| Future "fathom" | I | will fathom | |
| Future continuous "fathom" | I | will be fathoming | |
| Future perfect "fathom" | I | will have fathomed | |
| Future perfect continuous "fathom" | I | will have been fathoming |