I could click you could click he could click we could click you could click they could click
V-ing form
I could be clicking you could be clicking he could be clicking we could be clicking you could be clicking they could be clicking
Perfect
I could have clicked you could have clicked he could have clicked we could have clicked you could have clicked they could have clicked
V-ing perfect
I could have been clicking you could have been clicking he could have been clicking we could have been clicking you could have been clicking they could have been clicking
Negation
Simple form
I could not click you could not click he could not click we could not click you could not click they could not click
V-ing form
I could not be clicking you could not be clicking he could not be clicking we could not be clicking you could not be clicking they could not be clicking
Perfect
I could not have clicked you could not have clicked he could not have clicked we could not have clicked you could not have clicked they could not have clicked
V-ing perfect
I could not have been clicking you could not have been clicking he could not have been clicking we could not have been clicking you could not have been clicking they could not have been clicking
Interrogative form
Simple form
could I click? could you click? could he click? could we click? could you click? could they click?
V-ing form
could I be clicking? could you be clicking? could he be clicking? could we be clicking? could you be clicking? could they be clicking?
Perfect
could I have clicked? could you have clicked? could he have clicked? could we have clicked? could you have clicked? could they have clicked?
V-ing perfect
could I have been clicking? could you have been clicking? could he have been clicking? could we have been clicking? could you have been clicking? could they have been clicking?
Interro-negative form
Simple form
could I not click? could you not click? could he not click? could we not click? could you not click? could they not click?
V-ing form
could I not be clicking? could you not be clicking? could he not be clicking? could we not be clicking? could you not be clicking? could they not be clicking?
Perfect
could I not have clicked? could you not have clicked? could he not have clicked? could we not have clicked? could you not have clicked? could they not have clicked?
V-ing perfect
could I not have been clicking? could you not have been clicking? could he not have been clicking? could we not have been clicking? could you not have been clicking? could they not have been clicking?