I must marvel you must marvel he must marvel we must marvel you must marvel they must marvel
V-ing form
I must be marvelling you must be marvelling he must be marvelling we must be marvelling you must be marvelling they must be marvelling
Perfect
I must have marvelled you must have marvelled he must have marvelled we must have marvelled you must have marvelled they must have marvelled
V-ing perfect
I must have been marvelling you must have been marvelling he must have been marvelling we must have been marvelling you must have been marvelling they must have been marvelling
Negation
Simple form
I mustn't marvel you mustn't marvel he mustn't marvel we mustn't marvel you mustn't marvel they mustn't marvel
V-ing form
I mustn't be marvelling you mustn't be marvelling he mustn't be marvelling we mustn't be marvelling you mustn't be marvelling they mustn't be marvelling
Perfect
I mustn't have marvelled you mustn't have marvelled he mustn't have marvelled we mustn't have marvelled you mustn't have marvelled they mustn't have marvelled
V-ing perfect
I mustn't have been marvelling you mustn't have been marvelling he mustn't have been marvelling we mustn't have been marvelling you mustn't have been marvelling they mustn't have been marvelling
Interrogative form
Simple form
must I marvel? must you marvel? must he marvel? must we marvel? must you marvel? must they marvel?
V-ing form
must I be marvelling? must you be marvelling? must he be marvelling? must we be marvelling? must you be marvelling? must they be marvelling?
Perfect
must I have marvelled? must you have marvelled? must he have marvelled? must we have marvelled? must you have marvelled? must they have marvelled?
V-ing perfect
must I have been marvelling? must you have been marvelling? must he have been marvelling? must we have been marvelling? must you have been marvelling? must they have been marvelling?
Interro-negative form
Simple form
mustn't I marvel? mustn't you marvel? mustn't he marvel? mustn't we marvel? mustn't you marvel? mustn't they marvel?
V-ing form
mustn't I be marvelling? mustn't you be marvelling? mustn't he be marvelling? mustn't we be marvelling? mustn't you be marvelling? mustn't they be marvelling?
Perfect
mustn't I have marvelled? mustn't you have marvelled? mustn't he have marvelled? mustn't we have marvelled? mustn't you have marvelled? mustn't they have marvelled?
V-ing perfect
mustn't I have been marvelling? mustn't you have been marvelling? mustn't he have been marvelling? mustn't we have been marvelling? mustn't you have been marvelling? mustn't they have been marvelling?