Present
| I | ascertain |
| You | ascertain |
| She | ascertains |
| We | ascertain |
| They | ascertain |
Past
| I | ascertained |
| You | ascertained |
| She | ascertained |
| We | ascertained |
| They | ascertained |
Perfect
| I | have | ascertained |
| You | have | ascertained |
| She | has | ascertained |
| We | have | ascertained |
| They | have | ascertained |
Future
| I | will | ascertain |
| You | will | ascertain |
| She | will | ascertain |
| We | will | ascertain |
| They | will | ascertain |
Past Perfect
| I | had | ascertained |
| You | had | ascertained |
| She | had | ascertained |
| We | had | ascertained |
| They | had | ascertained |
Future Perfect
| I | will | have | ascertained |
| You | will | have | ascertained |
| She | will | have | ascertained |
| We | will | have | ascertained |
| They | will | have | ascertained |
Present - Conditional
| I | would | ascertain |
| You | would | ascertain |
| She | would | ascertain |
| We | would | ascertain |
| They | would | ascertain |
Perfect - Conditional
| I | would | have | ascertained |
| You | would | have | ascertained |
| She | would | have | ascertained |
| We | would | have | ascertained |
| They | would | have | ascertained |