I must spy you must spy she must spy we must spy you must spy they must spy
V-ing form
I must be spying you must be spying she must be spying we must be spying you must be spying they must be spying
Perfect
I must have spied you must have spied she 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 she 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 she 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 she 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 she 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 she 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 she spy? must we spy? must you spy? must they spy?
V-ing form
must I be spying? must you be spying? must she be spying? must we be spying? must you be spying? must they be spying?
Perfect
must I have spied? must you have spied? must she 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 she 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 she 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 she 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 she 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 she have been spying? mustn't we have been spying? mustn't you have been spying? mustn't they have been spying?