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