| Present "underfeed" | I | underfeed | |
| Present Continuous "underfeed" | I | am underfeeding | |
| Simple past "underfeed" | I | underfed | |
| Past Continuous "underfeed" | I | was underfeeding | |
| Present perfect "underfeed" | I | have underfed | |
| Present perfect continuous "underfeed" | I | have been underfeeding | |
| Past perfect "underfeed" | I | had underfed | |
| Past perfect continuous "underfeed" | I | had been underfeeding | |
| Future "underfeed" | I | will underfeed | |
| Future continuous "underfeed" | I | will be underfeeding | |
| Future perfect "underfeed" | I | will have underfed | |
| Future perfect continuous "underfeed" | I | will have been underfeeding |