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