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