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