I could grasp you could grasp he could grasp we could grasp you could grasp they could grasp
V-ing form
I could be grasping you could be grasping he could be grasping we could be grasping you could be grasping they could be grasping
Perfect
I could have grasped you could have grasped he could have grasped we could have grasped you could have grasped they could have grasped
V-ing perfect
I could have been grasping you could have been grasping he could have been grasping we could have been grasping you could have been grasping they could have been grasping
Negation
Simple form
I could not grasp you could not grasp he could not grasp we could not grasp you could not grasp they could not grasp
V-ing form
I could not be grasping you could not be grasping he could not be grasping we could not be grasping you could not be grasping they could not be grasping
Perfect
I could not have grasped you could not have grasped he could not have grasped we could not have grasped you could not have grasped they could not have grasped
V-ing perfect
I could not have been grasping you could not have been grasping he could not have been grasping we could not have been grasping you could not have been grasping they could not have been grasping
Interrogative form
Simple form
could I grasp? could you grasp? could he grasp? could we grasp? could you grasp? could they grasp?
V-ing form
could I be grasping? could you be grasping? could he be grasping? could we be grasping? could you be grasping? could they be grasping?
Perfect
could I have grasped? could you have grasped? could he have grasped? could we have grasped? could you have grasped? could they have grasped?
V-ing perfect
could I have been grasping? could you have been grasping? could he have been grasping? could we have been grasping? could you have been grasping? could they have been grasping?
Interro-negative form
Simple form
could I not grasp? could you not grasp? could he not grasp? could we not grasp? could you not grasp? could they not grasp?
V-ing form
could I not be grasping? could you not be grasping? could he not be grasping? could we not be grasping? could you not be grasping? could they not be grasping?
Perfect
could I not have grasped? could you not have grasped? could he not have grasped? could we not have grasped? could you not have grasped? could they not have grasped?
V-ing perfect
could I not have been grasping? could you not have been grasping? could he not have been grasping? could we not have been grasping? could you not have been grasping? could they not have been grasping?