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