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