English verb conjugation
COULD SHEAF

Regular verb: sheaf - sheafed - sheafed

Affirmation

Simple form	V-ing form
I could sheaf you could sheaf he could sheaf we could sheaf you could sheaf they could sheaf	I could be sheafing you could be sheafing he could be sheafing we could be sheafing you could be sheafing they could be sheafing
Perfect	V-ing perfect
I could have sheafed you could have sheafed he could have sheafed we could have sheafed you could have sheafed they could have sheafed	I could have been sheafing you could have been sheafing he could have been sheafing we could have been sheafing you could have been sheafing they could have been sheafing

Negation

Simple form	V-ing form
I could not sheaf you could not sheaf he could not sheaf we could not sheaf you could not sheaf they could not sheaf	I could not be sheafing you could not be sheafing he could not be sheafing we could not be sheafing you could not be sheafing they could not be sheafing
Perfect	V-ing perfect
I could not have sheafed you could not have sheafed he could not have sheafed we could not have sheafed you could not have sheafed they could not have sheafed	I could not have been sheafing you could not have been sheafing he could not have been sheafing we could not have been sheafing you could not have been sheafing they could not have been sheafing

Interrogative form

Simple form	V-ing form
could I sheaf? could you sheaf? could he sheaf? could we sheaf? could you sheaf? could they sheaf?	could I be sheafing? could you be sheafing? could he be sheafing? could we be sheafing? could you be sheafing? could they be sheafing?
Perfect	V-ing perfect
could I have sheafed? could you have sheafed? could he have sheafed? could we have sheafed? could you have sheafed? could they have sheafed?	could I have been sheafing? could you have been sheafing? could he have been sheafing? could we have been sheafing? could you have been sheafing? could they have been sheafing?

Interro-negative form

Simple form	V-ing form
could I not sheaf? could you not sheaf? could he not sheaf? could we not sheaf? could you not sheaf? could they not sheaf?	could I not be sheafing? could you not be sheafing? could he not be sheafing? could we not be sheafing? could you not be sheafing? could they not be sheafing?
Perfect	V-ing perfect
could I not have sheafed? could you not have sheafed? could he not have sheafed? could we not have sheafed? could you not have sheafed? could they not have sheafed?	could I not have been sheafing? could you not have been sheafing? could he not have been sheafing? could we not have been sheafing? could you not have been sheafing? could they not have been sheafing?