| Present "contribute" | I | contribute | |
| Present Continuous "contribute" | I | am contributing | |
| Simple past "contribute" | I | contributed | |
| Past Continuous "contribute" | I | was contributing | |
| Present perfect "contribute" | I | have contributed | |
| Present perfect continuous "contribute" | I | have been contributing | |
| Past perfect "contribute" | I | had contributed | |
| Past perfect continuous "contribute" | I | had been contributing | |
| Future "contribute" | I | will contribute | |
| Future continuous "contribute" | I | will be contributing | |
| Future perfect "contribute" | I | will have contributed | |
| Future perfect continuous "contribute" | I | will have been contributing |