I could surprise you could surprise he could surprise we could surprise you could surprise they could surprise
V-ing form
I could be surprising you could be surprising he could be surprising we could be surprising you could be surprising they could be surprising
Perfect
I could have surprised you could have surprised he could have surprised we could have surprised you could have surprised they could have surprised
V-ing perfect
I could have been surprising you could have been surprising he could have been surprising we could have been surprising you could have been surprising they could have been surprising
Negation
Simple form
I could not surprise you could not surprise he could not surprise we could not surprise you could not surprise they could not surprise
V-ing form
I could not be surprising you could not be surprising he could not be surprising we could not be surprising you could not be surprising they could not be surprising
Perfect
I could not have surprised you could not have surprised he could not have surprised we could not have surprised you could not have surprised they could not have surprised
V-ing perfect
I could not have been surprising you could not have been surprising he could not have been surprising we could not have been surprising you could not have been surprising they could not have been surprising
Interrogative form
Simple form
could I surprise? could you surprise? could he surprise? could we surprise? could you surprise? could they surprise?
V-ing form
could I be surprising? could you be surprising? could he be surprising? could we be surprising? could you be surprising? could they be surprising?
Perfect
could I have surprised? could you have surprised? could he have surprised? could we have surprised? could you have surprised? could they have surprised?
V-ing perfect
could I have been surprising? could you have been surprising? could he have been surprising? could we have been surprising? could you have been surprising? could they have been surprising?
Interro-negative form
Simple form
could I not surprise? could you not surprise? could he not surprise? could we not surprise? could you not surprise? could they not surprise?
V-ing form
could I not be surprising? could you not be surprising? could he not be surprising? could we not be surprising? could you not be surprising? could they not be surprising?
Perfect
could I not have surprised? could you not have surprised? could he not have surprised? could we not have surprised? could you not have surprised? could they not have surprised?
V-ing perfect
could I not have been surprising? could you not have been surprising? could he not have been surprising? could we not have been surprising? could you not have been surprising? could they not have been surprising?