| singular | plural |
| Infinitive | | |
| necessitate | |
| present simple | | |
| 1 | I necessitate | we necessitate |
| 2 | you necessitate | you necessitate |
| 3 | he/she/it necessitates | they necessitate |
| past simple | | |
| 1 | I necessitated | we necessitated |
| 2 | you necessitated | you necessitated |
| 3 | he/she/it necessitated | they necessitated |
| future simple | | |
| 1 | I will/shall necessitate | we will/shall necessitate |
| 2 | you will/shall necessitate | you will/shall necessitate |
| 3 | he/she/it will/shall necessitate | they will/shall necessitate |
| conditional simple | | |
| 1 | I would necessitate | we would necessitate |
| 2 | you would necessitate | you would necessitate |
| 3 | he/she/it would necessitate | they would necessitate |
| present continuous | | |
| 1 | I am necessitating | we are necessitating |
| 2 | you are necessitating | you are necessitating |
| 3 | he/she/it is necessitating | they are necessitating |
| past continuous | | |
| 1 | I was necessitating | we were necessitating |
| 2 | you were necessitating | you were necessitating |
| 3 | he/she/it was necessitating | they were necessitating |
| future continuous | | |
| 1 | I will be necessitating | we will be necessitating |
| 2 | you will be necessitating | you will be necessitating |
| 3 | he/she/it will be necessitating | they will be necessitating |
| conditional continuous | | |
| 1 | I would be necessitating | we would be necessitating |
| 2 | you would be necessitating | you would be necessitating |
| 3 | he/she/it would be necessitating | they would be necessitating |
| present perfect | | |
| 1 | I have necessitated | we have necessitated |
| 2 | you have necessitated | you have necessitated |
| 3 | he/she/it has necessitated | they have necessitated |
| past perfect | | |
| 1 | I had necessitated | we had necessitated |
| 2 | you had necessitated | you had necessitated |
| 3 | he/she/it had necessitated | they had necessitated |
| future perfect | | |
| 1 | I will have necessitated | we will have necessitated |
| 2 | you will have necessitated | you will have necessitated |
| 3 | he/she/it will have necessitated | they will have necessitated |
| conditional perfect | | |
| 1 | I would have necessitated | we would have necessitated |
| 2 | you would have necessitated | you would have necessitated |
| 3 | he/she/it would have necessitated | they would have necessitated |
