I could stipulate you could stipulate he could stipulate we could stipulate you could stipulate they could stipulate
V-ing form
I could be stipulating you could be stipulating he could be stipulating we could be stipulating you could be stipulating they could be stipulating
Perfect
I could have stipulated you could have stipulated he could have stipulated we could have stipulated you could have stipulated they could have stipulated
V-ing perfect
I could have been stipulating you could have been stipulating he could have been stipulating we could have been stipulating you could have been stipulating they could have been stipulating
Negation
Simple form
I could not stipulate you could not stipulate he could not stipulate we could not stipulate you could not stipulate they could not stipulate
V-ing form
I could not be stipulating you could not be stipulating he could not be stipulating we could not be stipulating you could not be stipulating they could not be stipulating
Perfect
I could not have stipulated you could not have stipulated he could not have stipulated we could not have stipulated you could not have stipulated they could not have stipulated
V-ing perfect
I could not have been stipulating you could not have been stipulating he could not have been stipulating we could not have been stipulating you could not have been stipulating they could not have been stipulating
Interrogative form
Simple form
could I stipulate? could you stipulate? could he stipulate? could we stipulate? could you stipulate? could they stipulate?
V-ing form
could I be stipulating? could you be stipulating? could he be stipulating? could we be stipulating? could you be stipulating? could they be stipulating?
Perfect
could I have stipulated? could you have stipulated? could he have stipulated? could we have stipulated? could you have stipulated? could they have stipulated?
V-ing perfect
could I have been stipulating? could you have been stipulating? could he have been stipulating? could we have been stipulating? could you have been stipulating? could they have been stipulating?
Interro-negative form
Simple form
could I not stipulate? could you not stipulate? could he not stipulate? could we not stipulate? could you not stipulate? could they not stipulate?
V-ing form
could I not be stipulating? could you not be stipulating? could he not be stipulating? could we not be stipulating? could you not be stipulating? could they not be stipulating?
Perfect
could I not have stipulated? could you not have stipulated? could he not have stipulated? could we not have stipulated? could you not have stipulated? could they not have stipulated?
V-ing perfect
could I not have been stipulating? could you not have been stipulating? could he not have been stipulating? could we not have been stipulating? could you not have been stipulating? could they not have been stipulating?