could octuple
Regular verb: octuple - octupled- octupled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could octuple
you could octuple
he could octuple
we could octuple
you could octuple
they could octuple 	I could be octupling
you could be octupling
he could be octupling
we could be octupling
you could be octupling
they could be octupling	I could have octupled
you could have octupled
he could have octupled
we could have octupled
you could have octupled
they could have octupled	I could have been octupling
you could have been octupling
he could have been octupling
we could have been octupling
you could have been octupling
they could have been octupling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't octuple
you couldn't octuple
he couldn't octuple
we couldn't octuple
you couldn't octuple
they couldn't octuple 	I couldn't be octupling
you couldn't be octupling
he couldn't be octupling
we couldn't be octupling
you couldn't be octupling
they couldn't be octupling	I couldn't have octupled
you couldn't have octupled
he couldn't have octupled
we couldn't have octupled
you couldn't have octupled
they couldn't have octupled	I couldn't have been octupling
you couldn't have been octupling
he couldn't have been octupling
we couldn't have been octupling
you couldn't have been octupling
they couldn't have been octupling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I octuple?
could you octuple?
could he octuple?
could we octuple?
could you octuple?
could they octuple? 	could I be octupling?
could you be octupling?
could he be octupling?
could we be octupling?
could you be octupling?
could they be octupling? 	could I have octupled?
could you have octupled?
could he have octupled?
could we have octupled?
could you have octupled?
could they have octupled? 	could I have been octupling?
could you have been octupling?
could he have been octupling?
could we have been octupling?
could you have been octupling?
could they have been octupling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I octuple?
couldn't you octuple?
couldn't he octuple?
couldn't we octuple?
couldn't you octuple?
couldn't they octuple? 	couldn't I be octupling?
couldn't you be octupling?
couldn't he be octupling?
couldn't we be octupling?
couldn't you be octupling?
couldn't they be octupling? 	couldn't I have octupled?
couldn't you have octupled?
couldn't he have octupled?
couldn't we have octupled?
couldn't you have octupled?
couldn't they have octupled? 	couldn't I have been octupling?
couldn't you have been octupling?
couldn't he have been octupling?
couldn't we have been octupling?
couldn't you have been octupling?
couldn't they have been octupling?