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