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