English verb conjugation
COULD HAPPEN
Regular verb: happen - happened - happened
Simple form | V-ing form |
| - - it could happen - - - | - - it could be happening - - - |
Perfect | V-ing perfect |
| - - it could have happened - - - | - - it could have been happening - - - |
Simple form | V-ing form |
| - - it couldn't happen - - - | - - it couldn't be happening - - - |
Perfect | V-ing perfect |
| - - it couldn't have happened - - - | - - it couldn't have been happening - - - |
Simple form | V-ing form |
| - - could it happen? - - - | - - could it be happening? - - - |
Perfect | V-ing perfect |
| - - could it have happened? - - - | - - could it have been happening? - - - |
Simple form | V-ing form |
| - - couldn't it happen? - - - | - - couldn't it be happening? - - - |
Perfect | V-ing perfect |
| - - couldn't it have happened? - - - | - - couldn't it have been happening? - - - |