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