| Present "blacken" | I | blacken | |
| Present Continuous "blacken" | I | am blackening | |
| Simple past "blacken" | I | blackened | |
| Past Continuous "blacken" | I | was blackening | |
| Present perfect "blacken" | I | have blackened | |
| Present perfect continuous "blacken" | I | have been blackening | |
| Past perfect "blacken" | I | had blackened | |
| Past perfect continuous "blacken" | I | had been blackening | |
| Future "blacken" | I | will blacken | |
| Future continuous "blacken" | I | will be blackening | |
| Future perfect "blacken" | I | will have blackened | |
| Future perfect continuous "blacken" | I | will have been blackening |