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