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