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