Present
| I | happen |
| You | happen |
| She | happens |
| We | happen |
| They | happen |
Past
| I | happened |
| You | happened |
| She | happened |
| We | happened |
| They | happened |
Perfect
| I | have | happened |
| You | have | happened |
| She | has | happened |
| We | have | happened |
| They | have | happened |
Future
| I | will | happen |
| You | will | happen |
| She | will | happen |
| We | will | happen |
| They | will | happen |
Past Perfect
| I | had | happened |
| You | had | happened |
| She | had | happened |
| We | had | happened |
| They | had | happened |
Future Perfect
| I | will | have | happened |
| You | will | have | happened |
| She | will | have | happened |
| We | will | have | happened |
| They | will | have | happened |
Present - Conditional
| I | would | happen |
| You | would | happen |
| She | would | happen |
| We | would | happen |
| They | would | happen |
Perfect - Conditional
| I | would | have | happened |
| You | would | have | happened |
| She | would | have | happened |
| We | would | have | happened |
| They | would | have | happened |