
Regular verb: happen - happened - happened
Simple form | V-ing form |
| - - it'd happen - - - | - - it'd be happening - - - |
Perfect | V-ing perfect |
| - - it would've happened - - - | - - it would've been happening - - - |
Simple form | V-ing form |
| - - it wouldn't happen - - - | - - it wouldn't be happening - - - |
Perfect | V-ing perfect |
| - - it wouldn't have happened - - - | - - it wouldn't have been happening - - - |
Simple form | V-ing form |
| - - would it happen? - - - | - - would it be happening? - - - |
Perfect | V-ing perfect |
| - - would it have happened? - - - | - - would it have been happening? - - - |
Simple form | V-ing form |
| - - wouldn't it happen? - - - | - - wouldn't it be happening? - - - |
Perfect | V-ing perfect |
| - - wouldn't it have happened? - - - | - - wouldn't it have been happening? - - - |