I could front-page you could front-page he could front-page we could front-page you could front-page they could front-page
V-ing form
I could be front-paging you could be front-paging he could be front-paging we could be front-paging you could be front-paging they could be front-paging
Perfect
I could have front-paged you could have front-paged he could have front-paged we could have front-paged you could have front-paged they could have front-paged
V-ing perfect
I could have been front-paging you could have been front-paging he could have been front-paging we could have been front-paging you could have been front-paging they could have been front-paging
Negation
Simple form
I couldn't front-page you couldn't front-page he couldn't front-page we couldn't front-page you couldn't front-page they couldn't front-page
V-ing form
I couldn't be front-paging you couldn't be front-paging he couldn't be front-paging we couldn't be front-paging you couldn't be front-paging they couldn't be front-paging
Perfect
I couldn't have front-paged you couldn't have front-paged he couldn't have front-paged we couldn't have front-paged you couldn't have front-paged they couldn't have front-paged
V-ing perfect
I couldn't have been front-paging you couldn't have been front-paging he couldn't have been front-paging we couldn't have been front-paging you couldn't have been front-paging they couldn't have been front-paging
Interrogative form
Simple form
could I front-page? could you front-page? could he front-page? could we front-page? could you front-page? could they front-page?
V-ing form
could I be front-paging? could you be front-paging? could he be front-paging? could we be front-paging? could you be front-paging? could they be front-paging?
Perfect
could I have front-paged? could you have front-paged? could he have front-paged? could we have front-paged? could you have front-paged? could they have front-paged?
V-ing perfect
could I have been front-paging? could you have been front-paging? could he have been front-paging? could we have been front-paging? could you have been front-paging? could they have been front-paging?
Interro-negative form
Simple form
couldn't I front-page? couldn't you front-page? couldn't he front-page? couldn't we front-page? couldn't you front-page? couldn't they front-page?
V-ing form
couldn't I be front-paging? couldn't you be front-paging? couldn't he be front-paging? couldn't we be front-paging? couldn't you be front-paging? couldn't they be front-paging?
Perfect
couldn't I have front-paged? couldn't you have front-paged? couldn't he have front-paged? couldn't we have front-paged? couldn't you have front-paged? couldn't they have front-paged?
V-ing perfect
couldn't I have been front-paging? couldn't you have been front-paging? couldn't he have been front-paging? couldn't we have been front-paging? couldn't you have been front-paging? couldn't they have been front-paging?