
Regular verb: stop - stopped - stopped
Simple form | V-ing form | 
| I must stop you must stop she must stop we must stop you must stop they must stop  | I must be stopping you must be stopping she must be stopping we must be stopping you must be stopping they must be stopping  | 
Perfect | V-ing perfect | 
| I must have stopped you must have stopped she must have stopped we must have stopped you must have stopped they must have stopped  | I must have been stopping you must have been stopping she must have been stopping we must have been stopping you must have been stopping they must have been stopping  | 
Simple form | V-ing form | 
| I mustn't stop you mustn't stop she mustn't stop we mustn't stop you mustn't stop they mustn't stop  | I mustn't be stopping you mustn't be stopping she mustn't be stopping we mustn't be stopping you mustn't be stopping they mustn't be stopping  | 
Perfect | V-ing perfect | 
| I mustn't have stopped you mustn't have stopped she mustn't have stopped we mustn't have stopped you mustn't have stopped they mustn't have stopped  | I mustn't have been stopping you mustn't have been stopping she mustn't have been stopping we mustn't have been stopping you mustn't have been stopping they mustn't have been stopping  | 
Simple form | V-ing form | 
| must I stop? must you stop? must she stop? must we stop? must you stop? must they stop?  | must I be stopping? must you be stopping? must she be stopping? must we be stopping? must you be stopping? must they be stopping?  | 
Perfect | V-ing perfect | 
| must I have stopped? must you have stopped? must she have stopped? must we have stopped? must you have stopped? must they have stopped?  | must I have been stopping? must you have been stopping? must she have been stopping? must we have been stopping? must you have been stopping? must they have been stopping?  | 
Simple form | V-ing form | 
| mustn't I stop? mustn't you stop? mustn't she stop? mustn't we stop? mustn't you stop? mustn't they stop?  | mustn't I be stopping? mustn't you be stopping? mustn't she be stopping? mustn't we be stopping? mustn't you be stopping? mustn't they be stopping?  | 
Perfect | V-ing perfect | 
| mustn't I have stopped? mustn't you have stopped? mustn't she have stopped? mustn't we have stopped? mustn't you have stopped? mustn't they have stopped?  | mustn't I have been stopping? mustn't you have been stopping? mustn't she have been stopping? mustn't we have been stopping? mustn't you have been stopping? mustn't they have been stopping?  |