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