I could bobbie you could bobbie he could bobbie we could bobbie you could bobbie they could bobbie
V-ing form
I could be bobbying you could be bobbying he could be bobbying we could be bobbying you could be bobbying they could be bobbying
Perfect
I could have bobbied you could have bobbied he could have bobbied we could have bobbied you could have bobbied they could have bobbied
V-ing perfect
I could have been bobbying you could have been bobbying he could have been bobbying we could have been bobbying you could have been bobbying they could have been bobbying
Negation
Simple form
I could not bobbie you could not bobbie he could not bobbie we could not bobbie you could not bobbie they could not bobbie
V-ing form
I could not be bobbying you could not be bobbying he could not be bobbying we could not be bobbying you could not be bobbying they could not be bobbying
Perfect
I could not have bobbied you could not have bobbied he could not have bobbied we could not have bobbied you could not have bobbied they could not have bobbied
V-ing perfect
I could not have been bobbying you could not have been bobbying he could not have been bobbying we could not have been bobbying you could not have been bobbying they could not have been bobbying
Interrogative form
Simple form
could I bobbie? could you bobbie? could he bobbie? could we bobbie? could you bobbie? could they bobbie?
V-ing form
could I be bobbying? could you be bobbying? could he be bobbying? could we be bobbying? could you be bobbying? could they be bobbying?
Perfect
could I have bobbied? could you have bobbied? could he have bobbied? could we have bobbied? could you have bobbied? could they have bobbied?
V-ing perfect
could I have been bobbying? could you have been bobbying? could he have been bobbying? could we have been bobbying? could you have been bobbying? could they have been bobbying?
Interro-negative form
Simple form
could I not bobbie? could you not bobbie? could he not bobbie? could we not bobbie? could you not bobbie? could they not bobbie?
V-ing form
could I not be bobbying? could you not be bobbying? could he not be bobbying? could we not be bobbying? could you not be bobbying? could they not be bobbying?
Perfect
could I not have bobbied? could you not have bobbied? could he not have bobbied? could we not have bobbied? could you not have bobbied? could they not have bobbied?
V-ing perfect
could I not have been bobbying? could you not have been bobbying? could he not have been bobbying? could we not have been bobbying? could you not have been bobbying? could they not have been bobbying?