I could busy you could busy he could busy we could busy you could busy they could busy
V-ing form
I could be busying you could be busying he could be busying we could be busying you could be busying they could be busying
Perfect
I could have busied you could have busied he could have busied we could have busied you could have busied they could have busied
V-ing perfect
I could have been busying you could have been busying he could have been busying we could have been busying you could have been busying they could have been busying
Negation
Simple form
I could not busy you could not busy he could not busy we could not busy you could not busy they could not busy
V-ing form
I could not be busying you could not be busying he could not be busying we could not be busying you could not be busying they could not be busying
Perfect
I could not have busied you could not have busied he could not have busied we could not have busied you could not have busied they could not have busied
V-ing perfect
I could not have been busying you could not have been busying he could not have been busying we could not have been busying you could not have been busying they could not have been busying
Interrogative form
Simple form
could I busy? could you busy? could he busy? could we busy? could you busy? could they busy?
V-ing form
could I be busying? could you be busying? could he be busying? could we be busying? could you be busying? could they be busying?
Perfect
could I have busied? could you have busied? could he have busied? could we have busied? could you have busied? could they have busied?
V-ing perfect
could I have been busying? could you have been busying? could he have been busying? could we have been busying? could you have been busying? could they have been busying?
Interro-negative form
Simple form
could I not busy? could you not busy? could he not busy? could we not busy? could you not busy? could they not busy?
V-ing form
could I not be busying? could you not be busying? could he not be busying? could we not be busying? could you not be busying? could they not be busying?
Perfect
could I not have busied? could you not have busied? could he not have busied? could we not have busied? could you not have busied? could they not have busied?
V-ing perfect
could I not have been busying? could you not have been busying? could he not have been busying? could we not have been busying? could you not have been busying? could they not have been busying?