| Simple | Progressive | Perfect | Progressive |
| Present |
| I investigate |
| you investigate |
| he/she/it investigates |
| we investigate |
| you all investigate |
| they investigate |
|
| I am investigating |
| you are investigating |
| he/she/it is investigating |
| we are investigating |
| you all are investigating |
| they are investigating |
|
| I have investigated |
| you have investigated |
| he/she/it has investigated |
| we have investigated |
| you all have investigated |
| they have investigated |
|
| I have been investigating |
| you have been investigating |
| he/she/it has been investigating |
| we have been investigating |
| you all have been investigating |
| they have been investigating |
|
| Past |
| I investigated |
| you investigated |
| he/she/it investigated |
| we investigated |
| you all investigated |
| they investigated |
|
| I was investigating |
| you were investigating |
| he/she/it was investigating |
| we were investigating |
| you all were investigating |
| they were investigating |
|
| I had investigated |
| you had investigated |
| he/she/it had investigated |
| we had investigated |
| you all had investigated |
| they had investigated |
|
| I had been investigating |
| you had been investigating |
| he/she/it had been investigating |
| we had been investigating |
| you all had been investigating |
| they had been investigating |
|
| Future |
| I will investigate |
| you will investigate |
| he/she/it will investigate |
| we will investigate |
| you all will investigate |
| they will investigate |
|
| I will be investigating |
| you will be investigating |
| he/she/it will be investigating |
| we are investigating |
| you all will be investigating |
| they will be investigating |
|
| I will have investigated |
| you will have investigated |
| he/she/it will have investigated |
| we will have investigated |
| you all will have investigated |
| they will have investigated |
|
| I will have been investigating |
| you will have been investigating |
| he/she/it will have been investigating |
| we will have been investigating |
| you all will have been investigating |
| they will have been investigating |
|
