| Present "investigate" | I | investigate | |
| Present Continuous "investigate" | I | am investigating | |
| Simple past "investigate" | I | investigated | |
| Past Continuous "investigate" | I | was investigating | |
| Present perfect "investigate" | I | have investigated | |
| Present perfect continuous "investigate" | I | have been investigating | |
| Past perfect "investigate" | I | had investigated | |
| Past perfect continuous "investigate" | I | had been investigating | |
| Future "investigate" | I | will investigate | |
| Future continuous "investigate" | I | will be investigating | |
| Future perfect "investigate" | I | will have investigated | |
| Future perfect continuous "investigate" | I | will have been investigating |