could decuple
Regular verb: decuple - decupled- decupled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could decuple
you could decuple
she could decuple
we could decuple
you could decuple
they could decuple 	I could be decupling
you could be decupling
she could be decupling
we could be decupling
you could be decupling
they could be decupling	I could have decupled
you could have decupled
she could have decupled
we could have decupled
you could have decupled
they could have decupled	I could have been decupling
you could have been decupling
she could have been decupling
we could have been decupling
you could have been decupling
they could have been decupling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not decuple
you could not decuple
she could not decuple
we could not decuple
you could not decuple
they could not decuple 	I could not be decupling
you could not be decupling
she could not be decupling
we could not be decupling
you could not be decupling
they could not be decupling	I could not have decupled
you could not have decupled
she could not have decupled
we could not have decupled
you could not have decupled
they could not have decupled	I could not have been decupling
you could not have been decupling
she could not have been decupling
we could not have been decupling
you could not have been decupling
they could not have been decupling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I decuple?
could you decuple?
could she decuple?
could we decuple?
could you decuple?
could they decuple? 	could I be decupling?
could you be decupling?
could she be decupling?
could we be decupling?
could you be decupling?
could they be decupling? 	could I have decupled?
could you have decupled?
could she have decupled?
could we have decupled?
could you have decupled?
could they have decupled? 	could I have been decupling?
could you have been decupling?
could she have been decupling?
could we have been decupling?
could you have been decupling?
could they have been decupling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not decuple?
could you not decuple?
could she not decuple?
could we not decuple?
could you not decuple?
could they not decuple? 	could I not be decupling?
could you not be decupling?
could she not be decupling?
could we not be decupling?
could you not be decupling?
could they not be decupling? 	could I not have decupled?
could you not have decupled?
could she not have decupled?
could we not have decupled?
could you not have decupled?
could they not have decupled? 	could I not have been decupling?
could you not have been decupling?
could she not have been decupling?
could we not have been decupling?
could you not have been decupling?
could they not have been decupling?