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