I could blitz you could blitz he could blitz we could blitz you could blitz they could blitz
V-ing form
I could be blitzing you could be blitzing he could be blitzing we could be blitzing you could be blitzing they could be blitzing
Perfect
I could have blitzed you could have blitzed he could have blitzed we could have blitzed you could have blitzed they could have blitzed
V-ing perfect
I could have been blitzing you could have been blitzing he could have been blitzing we could have been blitzing you could have been blitzing they could have been blitzing
Negation
Simple form
I couldn't blitz you couldn't blitz he couldn't blitz we couldn't blitz you couldn't blitz they couldn't blitz
V-ing form
I couldn't be blitzing you couldn't be blitzing he couldn't be blitzing we couldn't be blitzing you couldn't be blitzing they couldn't be blitzing
Perfect
I couldn't have blitzed you couldn't have blitzed he couldn't have blitzed we couldn't have blitzed you couldn't have blitzed they couldn't have blitzed
V-ing perfect
I couldn't have been blitzing you couldn't have been blitzing he couldn't have been blitzing we couldn't have been blitzing you couldn't have been blitzing they couldn't have been blitzing
Interrogative form
Simple form
could I blitz? could you blitz? could he blitz? could we blitz? could you blitz? could they blitz?
V-ing form
could I be blitzing? could you be blitzing? could he be blitzing? could we be blitzing? could you be blitzing? could they be blitzing?
Perfect
could I have blitzed? could you have blitzed? could he have blitzed? could we have blitzed? could you have blitzed? could they have blitzed?
V-ing perfect
could I have been blitzing? could you have been blitzing? could he have been blitzing? could we have been blitzing? could you have been blitzing? could they have been blitzing?
Interro-negative form
Simple form
couldn't I blitz? couldn't you blitz? couldn't he blitz? couldn't we blitz? couldn't you blitz? couldn't they blitz?
V-ing form
couldn't I be blitzing? couldn't you be blitzing? couldn't he be blitzing? couldn't we be blitzing? couldn't you be blitzing? couldn't they be blitzing?
Perfect
couldn't I have blitzed? couldn't you have blitzed? couldn't he have blitzed? couldn't we have blitzed? couldn't you have blitzed? couldn't they have blitzed?
V-ing perfect
couldn't I have been blitzing? couldn't you have been blitzing? couldn't he have been blitzing? couldn't we have been blitzing? couldn't you have been blitzing? couldn't they have been blitzing?