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