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