| Presente (Present) "doubt" | I | doubt | |
| Presente continuo (Present Continuous) "doubt" | I | am doubting | |
| Pasado simple (Simple past) "doubt" | I | doubted | |
| Pasado continuo (Past Continuous) "doubt" | I | was doubting | |
| Presente perfecto (Present perfect) "doubt" | I | have doubted | |
| Presente perfecto continuo (Present perfect continuous) "doubt" | I | have been doubting | |
| Pasado perfecto (Past perfect) "doubt" | I | had doubted | |
| Pasado perfecto continuo (Past perfect continuous) "doubt" | I | had been doubting | |
| Futuro (Future) "doubt" | I | will doubt | |
| Futuro continuo (Future continuous) "doubt" | I | will be doubting | |
| Futuro perfecto (Future perfect) "doubt" | I | will have doubted | |
| Futuro perfecto continuo (Future perfect continuous) "doubt" | I | will have been doubting |