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