I can dupe you can dupe she can dupe we can dupe you can dupe they can dupe
V-ing form
I can be duping you can be duping she can be duping we can be duping you can be duping they can be duping
Perfect
I can have duped you can have duped she can have duped we can have duped you can have duped they can have duped
V-ing perfect
I can have been duping you can have been duping she can have been duping we can have been duping you can have been duping they can have been duping
Negation
Simple form
I can't dupe you can't dupe she can't dupe we can't dupe you can't dupe they can't dupe
V-ing form
I can't be duping you can't be duping she can't be duping we can't be duping you can't be duping they can't be duping
Perfect
I can't have duped you can't have duped she can't have duped we can't have duped you can't have duped they can't have duped
V-ing perfect
I can't have been duping you can't have been duping she can't have been duping we can't have been duping you can't have been duping they can't have been duping
Interrogative form
Simple form
can I dupe? can you dupe? can she dupe? can we dupe? can you dupe? can they dupe?
V-ing form
can I be duping? can you be duping? can she be duping? can we be duping? can you be duping? can they be duping?
Perfect
can I have duped? can you have duped? can she have duped? can we have duped? can you have duped? can they have duped?
V-ing perfect
can I have been duping? can you have been duping? can she have been duping? can we have been duping? can you have been duping? can they have been duping?
Interro-negative form
Simple form
can't I dupe? can't you dupe? can't she dupe? can't we dupe? can't you dupe? can't they dupe?
V-ing form
can't I be duping? can't you be duping? can't she be duping? can't we be duping? can't you be duping? can't they be duping?
Perfect
can't I have duped? can't you have duped? can't she have duped? can't we have duped? can't you have duped? can't they have duped?
V-ing perfect
can't I have been duping? can't you have been duping? can't she have been duping? can't we have been duping? can't you have been duping? can't they have been duping?