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