could interfold
Regular verb: interfold - interfolded- interfolded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could interfold
you could interfold
she could interfold
we could interfold
you could interfold
they could interfold 	I could be interfolding
you could be interfolding
she could be interfolding
we could be interfolding
you could be interfolding
they could be interfolding	I could have interfolded
you could have interfolded
she could have interfolded
we could have interfolded
you could have interfolded
they could have interfolded	I could have been interfolding
you could have been interfolding
she could have been interfolding
we could have been interfolding
you could have been interfolding
they could have been interfolding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't interfold
you couldn't interfold
she couldn't interfold
we couldn't interfold
you couldn't interfold
they couldn't interfold 	I couldn't be interfolding
you couldn't be interfolding
she couldn't be interfolding
we couldn't be interfolding
you couldn't be interfolding
they couldn't be interfolding	I couldn't have interfolded
you couldn't have interfolded
she couldn't have interfolded
we couldn't have interfolded
you couldn't have interfolded
they couldn't have interfolded	I couldn't have been interfolding
you couldn't have been interfolding
she couldn't have been interfolding
we couldn't have been interfolding
you couldn't have been interfolding
they couldn't have been interfolding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I interfold?
could you interfold?
could she interfold?
could we interfold?
could you interfold?
could they interfold? 	could I be interfolding?
could you be interfolding?
could she be interfolding?
could we be interfolding?
could you be interfolding?
could they be interfolding? 	could I have interfolded?
could you have interfolded?
could she have interfolded?
could we have interfolded?
could you have interfolded?
could they have interfolded? 	could I have been interfolding?
could you have been interfolding?
could she have been interfolding?
could we have been interfolding?
could you have been interfolding?
could they have been interfolding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I interfold?
couldn't you interfold?
couldn't she interfold?
couldn't we interfold?
couldn't you interfold?
couldn't they interfold? 	couldn't I be interfolding?
couldn't you be interfolding?
couldn't she be interfolding?
couldn't we be interfolding?
couldn't you be interfolding?
couldn't they be interfolding? 	couldn't I have interfolded?
couldn't you have interfolded?
couldn't she have interfolded?
couldn't we have interfolded?
couldn't you have interfolded?
couldn't they have interfolded? 	couldn't I have been interfolding?
couldn't you have been interfolding?
couldn't she have been interfolding?
couldn't we have been interfolding?
couldn't you have been interfolding?
couldn't they have been interfolding?