Regular verb: snow - snowed - snowed
Simple form | V-ing form |
- - it must snow - - - | - - it must be snowing - - - |
Perfect | V-ing perfect |
- - it must have snowed - - - | - - it must have been snowing - - - |
Simple form | V-ing form |
- - it must not snow - - - | - - it must not be snowing - - - |
Perfect | V-ing perfect |
- - it must not have snowed - - - | - - it must not have been snowing - - - |
Simple form | V-ing form |
- - must it snow? - - - | - - must it be snowing? - - - |
Perfect | V-ing perfect |
- - must it have snowed? - - - | - - must it have been snowing? - - - |
Simple form | V-ing form |
- - must it not snow? - - - | - - must it not be snowing? - - - |
Perfect | V-ing perfect |
- - must it not have snowed? - - - | - - must it not have been snowing? - - - |