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