I could blackmail you could blackmail she could blackmail we could blackmail you could blackmail they could blackmail
V-ing form
I could be blackmailing you could be blackmailing she could be blackmailing we could be blackmailing you could be blackmailing they could be blackmailing
Perfect
I could have blackmailed you could have blackmailed she could have blackmailed we could have blackmailed you could have blackmailed they could have blackmailed
V-ing perfect
I could have been blackmailing you could have been blackmailing she could have been blackmailing we could have been blackmailing you could have been blackmailing they could have been blackmailing
Negation
Simple form
I couldn't blackmail you couldn't blackmail she couldn't blackmail we couldn't blackmail you couldn't blackmail they couldn't blackmail
V-ing form
I couldn't be blackmailing you couldn't be blackmailing she couldn't be blackmailing we couldn't be blackmailing you couldn't be blackmailing they couldn't be blackmailing
Perfect
I couldn't have blackmailed you couldn't have blackmailed she couldn't have blackmailed we couldn't have blackmailed you couldn't have blackmailed they couldn't have blackmailed
V-ing perfect
I couldn't have been blackmailing you couldn't have been blackmailing she couldn't have been blackmailing we couldn't have been blackmailing you couldn't have been blackmailing they couldn't have been blackmailing
Interrogative form
Simple form
could I blackmail? could you blackmail? could she blackmail? could we blackmail? could you blackmail? could they blackmail?
V-ing form
could I be blackmailing? could you be blackmailing? could she be blackmailing? could we be blackmailing? could you be blackmailing? could they be blackmailing?
Perfect
could I have blackmailed? could you have blackmailed? could she have blackmailed? could we have blackmailed? could you have blackmailed? could they have blackmailed?
V-ing perfect
could I have been blackmailing? could you have been blackmailing? could she have been blackmailing? could we have been blackmailing? could you have been blackmailing? could they have been blackmailing?
Interro-negative form
Simple form
couldn't I blackmail? couldn't you blackmail? couldn't she blackmail? couldn't we blackmail? couldn't you blackmail? couldn't they blackmail?
V-ing form
couldn't I be blackmailing? couldn't you be blackmailing? couldn't she be blackmailing? couldn't we be blackmailing? couldn't you be blackmailing? couldn't they be blackmailing?
Perfect
couldn't I have blackmailed? couldn't you have blackmailed? couldn't she have blackmailed? couldn't we have blackmailed? couldn't you have blackmailed? couldn't they have blackmailed?
V-ing perfect
couldn't I have been blackmailing? couldn't you have been blackmailing? couldn't she have been blackmailing? couldn't we have been blackmailing? couldn't you have been blackmailing? couldn't they have been blackmailing?