I could implement you could implement he could implement we could implement you could implement they could implement
V-ing form
I could be implementing you could be implementing he could be implementing we could be implementing you could be implementing they could be implementing
Perfect
I could have implemented you could have implemented he could have implemented we could have implemented you could have implemented they could have implemented
V-ing perfect
I could have been implementing you could have been implementing he could have been implementing we could have been implementing you could have been implementing they could have been implementing
Negation
Simple form
I could not implement you could not implement he could not implement we could not implement you could not implement they could not implement
V-ing form
I could not be implementing you could not be implementing he could not be implementing we could not be implementing you could not be implementing they could not be implementing
Perfect
I could not have implemented you could not have implemented he could not have implemented we could not have implemented you could not have implemented they could not have implemented
V-ing perfect
I could not have been implementing you could not have been implementing he could not have been implementing we could not have been implementing you could not have been implementing they could not have been implementing
Interrogative form
Simple form
could I implement? could you implement? could he implement? could we implement? could you implement? could they implement?
V-ing form
could I be implementing? could you be implementing? could he be implementing? could we be implementing? could you be implementing? could they be implementing?
Perfect
could I have implemented? could you have implemented? could he have implemented? could we have implemented? could you have implemented? could they have implemented?
V-ing perfect
could I have been implementing? could you have been implementing? could he have been implementing? could we have been implementing? could you have been implementing? could they have been implementing?
Interro-negative form
Simple form
could I not implement? could you not implement? could he not implement? could we not implement? could you not implement? could they not implement?
V-ing form
could I not be implementing? could you not be implementing? could he not be implementing? could we not be implementing? could you not be implementing? could they not be implementing?
Perfect
could I not have implemented? could you not have implemented? could he not have implemented? could we not have implemented? could you not have implemented? could they not have implemented?
V-ing perfect
could I not have been implementing? could you not have been implementing? could he not have been implementing? could we not have been implementing? could you not have been implementing? could they not have been implementing?