I could poison you could poison he could poison we could poison you could poison they could poison
V-ing form
I could be poisoning you could be poisoning he could be poisoning we could be poisoning you could be poisoning they could be poisoning
Perfect
I could have poisoned you could have poisoned he could have poisoned we could have poisoned you could have poisoned they could have poisoned
V-ing perfect
I could have been poisoning you could have been poisoning he could have been poisoning we could have been poisoning you could have been poisoning they could have been poisoning
Negation
Simple form
I could not poison you could not poison he could not poison we could not poison you could not poison they could not poison
V-ing form
I could not be poisoning you could not be poisoning he could not be poisoning we could not be poisoning you could not be poisoning they could not be poisoning
Perfect
I could not have poisoned you could not have poisoned he could not have poisoned we could not have poisoned you could not have poisoned they could not have poisoned
V-ing perfect
I could not have been poisoning you could not have been poisoning he could not have been poisoning we could not have been poisoning you could not have been poisoning they could not have been poisoning
Interrogative form
Simple form
could I poison? could you poison? could he poison? could we poison? could you poison? could they poison?
V-ing form
could I be poisoning? could you be poisoning? could he be poisoning? could we be poisoning? could you be poisoning? could they be poisoning?
Perfect
could I have poisoned? could you have poisoned? could he have poisoned? could we have poisoned? could you have poisoned? could they have poisoned?
V-ing perfect
could I have been poisoning? could you have been poisoning? could he have been poisoning? could we have been poisoning? could you have been poisoning? could they have been poisoning?
Interro-negative form
Simple form
could I not poison? could you not poison? could he not poison? could we not poison? could you not poison? could they not poison?
V-ing form
could I not be poisoning? could you not be poisoning? could he not be poisoning? could we not be poisoning? could you not be poisoning? could they not be poisoning?
Perfect
could I not have poisoned? could you not have poisoned? could he not have poisoned? could we not have poisoned? could you not have poisoned? could they not have poisoned?
V-ing perfect
could I not have been poisoning? could you not have been poisoning? could he not have been poisoning? could we not have been poisoning? could you not have been poisoning? could they not have been poisoning?