
Verbe régulier : improve -  improved - improved
Traduction française : améliorer - s'améliorer 
Forme simple | Forme en V-ing | 
| I must improve you must improve he must improve we must improve you must improve they must improve  | I must be improving you must be improving he must be improving we must be improving you must be improving they must be improving  | 
Perfect | Perfect en V-ing | 
| I must have improved you must have improved he must have improved we must have improved you must have improved they must have improved  | I must have been improving you must have been improving he must have been improving we must have been improving you must have been improving they must have been improving  | 
Forme simple | Forme en V-ing | 
| I mustn't improve you mustn't improve he mustn't improve we mustn't improve you mustn't improve they mustn't improve  | I mustn't be improving you mustn't be improving he mustn't be improving we mustn't be improving you mustn't be improving they mustn't be improving  | 
Perfect | Perfect en V-ing | 
| I mustn't have improved you mustn't have improved he mustn't have improved we mustn't have improved you mustn't have improved they mustn't have improved  | I mustn't have been improving you mustn't have been improving he mustn't have been improving we mustn't have been improving you mustn't have been improving they mustn't have been improving  | 
Forme simple | Forme en V-ing | 
| must I improve? must you improve? must he improve? must we improve? must you improve? must they improve?  | must I be improving? must you be improving? must he be improving? must we be improving? must you be improving? must they be improving?  | 
Perfect | Perfect en V-ing | 
| must I have improved? must you have improved? must he have improved? must we have improved? must you have improved? must they have improved?  | must I have been improving? must you have been improving? must he have been improving? must we have been improving? must you have been improving? must they have been improving?  | 
Forme simple | Forme en V-ing | 
| mustn't I improve? mustn't you improve? mustn't he improve? mustn't we improve? mustn't you improve? mustn't they improve?  | mustn't I be improving? mustn't you be improving? mustn't he be improving? mustn't we be improving? mustn't you be improving? mustn't they be improving?  | 
Perfect | Perfect en V-ing | 
| mustn't I have improved? mustn't you have improved? mustn't he have improved? mustn't we have improved? mustn't you have improved? mustn't they have improved?  | mustn't I have been improving? mustn't you have been improving? mustn't he have been improving? mustn't we have been improving? mustn't you have been improving? mustn't they have been improving?  |