could dupe
Regular verb: dupe - duped- duped

Affirmation 	
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I could dupe
you could dupe
he could dupe
we could dupe
you could dupe
they could dupe 	I could be duping
you could be duping
he could be duping
we could be duping
you could be duping
they could be duping	I could have duped
you could have duped
he could have duped
we could have duped
you could have duped
they could have duped	I could have been duping
you could have been duping
he could have been duping
we could have been duping
you could have been duping
they could have been duping	

Negation 	
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I couldn't dupe
you couldn't dupe
he couldn't dupe
we couldn't dupe
you couldn't dupe
they couldn't dupe 	I couldn't be duping
you couldn't be duping
he couldn't be duping
we couldn't be duping
you couldn't be duping
they couldn't be duping	I couldn't have duped
you couldn't have duped
he couldn't have duped
we couldn't have duped
you couldn't have duped
they couldn't have duped	I couldn't have been duping
you couldn't have been duping
he couldn't have been duping
we couldn't have been duping
you couldn't have been duping
they couldn't have been duping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I dupe?
could you dupe?
could he dupe?
could we dupe?
could you dupe?
could they dupe? 	could I be duping?
could you be duping?
could he be duping?
could we be duping?
could you be duping?
could they be duping? 	could I have duped?
could you have duped?
could he have duped?
could we have duped?
could you have duped?
could they have duped? 	could I have been duping?
could you have been duping?
could he have been duping?
could we have been duping?
could you have been duping?
could they have been duping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I dupe?
couldn't you dupe?
couldn't he dupe?
couldn't we dupe?
couldn't you dupe?
couldn't they dupe? 	couldn't I be duping?
couldn't you be duping?
couldn't he be duping?
couldn't we be duping?
couldn't you be duping?
couldn't they be duping? 	couldn't I have duped?
couldn't you have duped?
couldn't he have duped?
couldn't we have duped?
couldn't you have duped?
couldn't they have duped? 	couldn't I have been duping?
couldn't you have been duping?
couldn't he have been duping?
couldn't we have been duping?
couldn't you have been duping?
couldn't they have been duping?