could shred
Regular verb: shred - shredded- shredded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could shred
you could shred
she could shred
we could shred
you could shred
they could shred 	I could be shredding
you could be shredding
she could be shredding
we could be shredding
you could be shredding
they could be shredding	I could have shredded
you could have shredded
she could have shredded
we could have shredded
you could have shredded
they could have shredded	I could have been shredding
you could have been shredding
she could have been shredding
we could have been shredding
you could have been shredding
they could have been shredding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't shred
you couldn't shred
she couldn't shred
we couldn't shred
you couldn't shred
they couldn't shred 	I couldn't be shredding
you couldn't be shredding
she couldn't be shredding
we couldn't be shredding
you couldn't be shredding
they couldn't be shredding	I couldn't have shredded
you couldn't have shredded
she couldn't have shredded
we couldn't have shredded
you couldn't have shredded
they couldn't have shredded	I couldn't have been shredding
you couldn't have been shredding
she couldn't have been shredding
we couldn't have been shredding
you couldn't have been shredding
they couldn't have been shredding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I shred?
could you shred?
could she shred?
could we shred?
could you shred?
could they shred? 	could I be shredding?
could you be shredding?
could she be shredding?
could we be shredding?
could you be shredding?
could they be shredding? 	could I have shredded?
could you have shredded?
could she have shredded?
could we have shredded?
could you have shredded?
could they have shredded? 	could I have been shredding?
could you have been shredding?
could she have been shredding?
could we have been shredding?
could you have been shredding?
could they have been shredding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I shred?
couldn't you shred?
couldn't she shred?
couldn't we shred?
couldn't you shred?
couldn't they shred? 	couldn't I be shredding?
couldn't you be shredding?
couldn't she be shredding?
couldn't we be shredding?
couldn't you be shredding?
couldn't they be shredding? 	couldn't I have shredded?
couldn't you have shredded?
couldn't she have shredded?
couldn't we have shredded?
couldn't you have shredded?
couldn't they have shredded? 	couldn't I have been shredding?
couldn't you have been shredding?
couldn't she have been shredding?
couldn't we have been shredding?
couldn't you have been shredding?
couldn't they have been shredding?