
Regular verb: snow - snowed - snowed
Simple form | V-ing form | 
| - - it can snow - - -  | - - it can be snowing - - -  | 
Perfect | V-ing perfect | 
| - - it can have snowed - - -  | - - it can have been snowing - - -  | 
Simple form | V-ing form | 
| - - it can't snow - - -  | - - it can't be snowing - - -  | 
Perfect | V-ing perfect | 
| - - it can't have snowed - - -  | - - it can't have been snowing - - -  | 
Simple form | V-ing form | 
| - - can it snow? - - -  | - - can it be snowing? - - -  | 
Perfect | V-ing perfect | 
| - - can it have snowed? - - -  | - - can it have been snowing? - - -  | 
Simple form | V-ing form | 
| - - can't it snow? - - -  | - - can't it be snowing? - - -  | 
Perfect | V-ing perfect | 
| - - can't it have snowed? - - -  | - - can't it have been snowing? - - -  |