
Irregular verb: forget - forgot - forgotten
Simple form | V-ing form | 
| I must forget you must forget she must forget we must forget you must forget they must forget  | I must be forgetting you must be forgetting she must be forgetting we must be forgetting you must be forgetting they must be forgetting  | 
Perfect | V-ing perfect | 
| I must have forgotten you must have forgotten she must have forgotten we must have forgotten you must have forgotten they must have forgotten  | I must have been forgetting you must have been forgetting she must have been forgetting we must have been forgetting you must have been forgetting they must have been forgetting  | 
Simple form | V-ing form | 
| I mustn't forget you mustn't forget she mustn't forget we mustn't forget you mustn't forget they mustn't forget  | I mustn't be forgetting you mustn't be forgetting she mustn't be forgetting we mustn't be forgetting you mustn't be forgetting they mustn't be forgetting  | 
Perfect | V-ing perfect | 
| I mustn't have forgotten you mustn't have forgotten she mustn't have forgotten we mustn't have forgotten you mustn't have forgotten they mustn't have forgotten  | I mustn't have been forgetting you mustn't have been forgetting she mustn't have been forgetting we mustn't have been forgetting you mustn't have been forgetting they mustn't have been forgetting  | 
Simple form | V-ing form | 
| must I forget? must you forget? must she forget? must we forget? must you forget? must they forget?  | must I be forgetting? must you be forgetting? must she be forgetting? must we be forgetting? must you be forgetting? must they be forgetting?  | 
Perfect | V-ing perfect | 
| must I have forgotten? must you have forgotten? must she have forgotten? must we have forgotten? must you have forgotten? must they have forgotten?  | must I have been forgetting? must you have been forgetting? must she have been forgetting? must we have been forgetting? must you have been forgetting? must they have been forgetting?  | 
Simple form | V-ing form | 
| mustn't I forget? mustn't you forget? mustn't she forget? mustn't we forget? mustn't you forget? mustn't they forget?  | mustn't I be forgetting? mustn't you be forgetting? mustn't she be forgetting? mustn't we be forgetting? mustn't you be forgetting? mustn't they be forgetting?  | 
Perfect | V-ing perfect | 
| mustn't I have forgotten? mustn't you have forgotten? mustn't she have forgotten? mustn't we have forgotten? mustn't you have forgotten? mustn't they have forgotten?  | mustn't I have been forgetting? mustn't you have been forgetting? mustn't she have been forgetting? mustn't we have been forgetting? mustn't you have been forgetting? mustn't they have been forgetting?  |