
Regular verb: while - whiled - whiled
Simple form | V-ing form | 
| I must while you must while he must while we must while you must while they must while  | I must be whiling you must be whiling he must be whiling we must be whiling you must be whiling they must be whiling  | 
Perfect | V-ing perfect | 
| I must have whiled you must have whiled he must have whiled we must have whiled you must have whiled they must have whiled  | I must have been whiling you must have been whiling he must have been whiling we must have been whiling you must have been whiling they must have been whiling  | 
Simple form | V-ing form | 
| I mustn't while you mustn't while he mustn't while we mustn't while you mustn't while they mustn't while  | I mustn't be whiling you mustn't be whiling he mustn't be whiling we mustn't be whiling you mustn't be whiling they mustn't be whiling  | 
Perfect | V-ing perfect | 
| I mustn't have whiled you mustn't have whiled he mustn't have whiled we mustn't have whiled you mustn't have whiled they mustn't have whiled  | I mustn't have been whiling you mustn't have been whiling he mustn't have been whiling we mustn't have been whiling you mustn't have been whiling they mustn't have been whiling  | 
Simple form | V-ing form | 
| must I while? must you while? must he while? must we while? must you while? must they while?  | must I be whiling? must you be whiling? must he be whiling? must we be whiling? must you be whiling? must they be whiling?  | 
Perfect | V-ing perfect | 
| must I have whiled? must you have whiled? must he have whiled? must we have whiled? must you have whiled? must they have whiled?  | must I have been whiling? must you have been whiling? must he have been whiling? must we have been whiling? must you have been whiling? must they have been whiling?  | 
Simple form | V-ing form | 
| mustn't I while? mustn't you while? mustn't he while? mustn't we while? mustn't you while? mustn't they while?  | mustn't I be whiling? mustn't you be whiling? mustn't he be whiling? mustn't we be whiling? mustn't you be whiling? mustn't they be whiling?  | 
Perfect | V-ing perfect | 
| mustn't I have whiled? mustn't you have whiled? mustn't he have whiled? mustn't we have whiled? mustn't you have whiled? mustn't they have whiled?  | mustn't I have been whiling? mustn't you have been whiling? mustn't he have been whiling? mustn't we have been whiling? mustn't you have been whiling? mustn't they have been whiling?  |