Present
| I | toughen |
| You | toughen |
| She | toughens |
| We | toughen |
| They | toughen |
Past
| I | toughened |
| You | toughened |
| She | toughened |
| We | toughened |
| They | toughened |
Perfect
| I | have | toughened |
| You | have | toughened |
| She | has | toughened |
| We | have | toughened |
| They | have | toughened |
Future
| I | will | toughen |
| You | will | toughen |
| She | will | toughen |
| We | will | toughen |
| They | will | toughen |
Past Perfect
| I | had | toughened |
| You | had | toughened |
| She | had | toughened |
| We | had | toughened |
| They | had | toughened |
Future Perfect
| I | will | have | toughened |
| You | will | have | toughened |
| She | will | have | toughened |
| We | will | have | toughened |
| They | will | have | toughened |
Present - Conditional
| I | would | toughen |
| You | would | toughen |
| She | would | toughen |
| We | would | toughen |
| They | would | toughen |
Perfect - Conditional
| I | would | have | toughened |
| You | would | have | toughened |
| She | would | have | toughened |
| We | would | have | toughened |
| They | would | have | toughened |