Present
| I | investigate |
| You | investigate |
| She | investigates |
| We | investigate |
| They | investigate |
Past
| I | investigated |
| You | investigated |
| She | investigated |
| We | investigated |
| They | investigated |
Perfect
| I | have | investigated |
| You | have | investigated |
| She | has | investigated |
| We | have | investigated |
| They | have | investigated |
Future
| I | will | investigate |
| You | will | investigate |
| She | will | investigate |
| We | will | investigate |
| They | will | investigate |
Past Perfect
| I | had | investigated |
| You | had | investigated |
| She | had | investigated |
| We | had | investigated |
| They | had | investigated |
Future Perfect
| I | will | have | investigated |
| You | will | have | investigated |
| She | will | have | investigated |
| We | will | have | investigated |
| They | will | have | investigated |
Present - Conditional
| I | would | investigate |
| You | would | investigate |
| She | would | investigate |
| We | would | investigate |
| They | would | investigate |
Perfect - Conditional
| I | would | have | investigated |
| You | would | have | investigated |
| She | would | have | investigated |
| We | would | have | investigated |
| They | would | have | investigated |