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