
Verbo irregular: freeze - froze - frozen
Forma simple | Forma com V-ing | 
| - - it could freeze - - -  | - - it could be freezing - - -  | 
Perfeito | Perfeito com V-ing | 
| - - it could have frozen - - -  | - - it could have been freezing - - -  | 
Forma simple | Forma com V-ing | 
| - - it could not freeze - - -  | - - it could not be freezing - - -  | 
Perfeito | Perfeito com V-ing | 
| - - it could not have frozen - - -  | - - it could not have been freezing - - -  | 
Forma simple | Forma com V-ing | 
| - - could it freeze? - - -  | - - could it be freezing? - - -  | 
Perfeito | Perfeito com V-ing | 
| - - could it have frozen? - - -  | - - could it have been freezing? - - -  | 
Forma simple | Forma com V-ing | 
| - - could it not freeze? - - -  | - - could it not be freezing? - - -  | 
Perfeito | Perfeito com V-ing | 
| - - could it not have frozen? - - -  | - - could it not have been freezing? - - -  |