I could blink you could blink he could blink we could blink you could blink they could blink
V-ing form
I could be blinking you could be blinking he could be blinking we could be blinking you could be blinking they could be blinking
Perfect
I could have blinked you could have blinked he could have blinked we could have blinked you could have blinked they could have blinked
V-ing perfect
I could have been blinking you could have been blinking he could have been blinking we could have been blinking you could have been blinking they could have been blinking
Negation
Simple form
I could not blink you could not blink he could not blink we could not blink you could not blink they could not blink
V-ing form
I could not be blinking you could not be blinking he could not be blinking we could not be blinking you could not be blinking they could not be blinking
Perfect
I could not have blinked you could not have blinked he could not have blinked we could not have blinked you could not have blinked they could not have blinked
V-ing perfect
I could not have been blinking you could not have been blinking he could not have been blinking we could not have been blinking you could not have been blinking they could not have been blinking
Interrogative form
Simple form
could I blink? could you blink? could he blink? could we blink? could you blink? could they blink?
V-ing form
could I be blinking? could you be blinking? could he be blinking? could we be blinking? could you be blinking? could they be blinking?
Perfect
could I have blinked? could you have blinked? could he have blinked? could we have blinked? could you have blinked? could they have blinked?
V-ing perfect
could I have been blinking? could you have been blinking? could he have been blinking? could we have been blinking? could you have been blinking? could they have been blinking?
Interro-negative form
Simple form
could I not blink? could you not blink? could he not blink? could we not blink? could you not blink? could they not blink?
V-ing form
could I not be blinking? could you not be blinking? could he not be blinking? could we not be blinking? could you not be blinking? could they not be blinking?
Perfect
could I not have blinked? could you not have blinked? could he not have blinked? could we not have blinked? could you not have blinked? could they not have blinked?
V-ing perfect
could I not have been blinking? could you not have been blinking? could he not have been blinking? could we not have been blinking? could you not have been blinking? could they not have been blinking?