could shack
Regular verb: shack - shacked- shacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could shack
you could shack
he could shack
we could shack
you could shack
they could shack 	I could be shacking
you could be shacking
he could be shacking
we could be shacking
you could be shacking
they could be shacking	I could have shacked
you could have shacked
he could have shacked
we could have shacked
you could have shacked
they could have shacked	I could have been shacking
you could have been shacking
he could have been shacking
we could have been shacking
you could have been shacking
they could have been shacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't shack
you couldn't shack
he couldn't shack
we couldn't shack
you couldn't shack
they couldn't shack 	I couldn't be shacking
you couldn't be shacking
he couldn't be shacking
we couldn't be shacking
you couldn't be shacking
they couldn't be shacking	I couldn't have shacked
you couldn't have shacked
he couldn't have shacked
we couldn't have shacked
you couldn't have shacked
they couldn't have shacked	I couldn't have been shacking
you couldn't have been shacking
he couldn't have been shacking
we couldn't have been shacking
you couldn't have been shacking
they couldn't have been shacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I shack?
could you shack?
could he shack?
could we shack?
could you shack?
could they shack? 	could I be shacking?
could you be shacking?
could he be shacking?
could we be shacking?
could you be shacking?
could they be shacking? 	could I have shacked?
could you have shacked?
could he have shacked?
could we have shacked?
could you have shacked?
could they have shacked? 	could I have been shacking?
could you have been shacking?
could he have been shacking?
could we have been shacking?
could you have been shacking?
could they have been shacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I shack?
couldn't you shack?
couldn't he shack?
couldn't we shack?
couldn't you shack?
couldn't they shack? 	couldn't I be shacking?
couldn't you be shacking?
couldn't he be shacking?
couldn't we be shacking?
couldn't you be shacking?
couldn't they be shacking? 	couldn't I have shacked?
couldn't you have shacked?
couldn't he have shacked?
couldn't we have shacked?
couldn't you have shacked?
couldn't they have shacked? 	couldn't I have been shacking?
couldn't you have been shacking?
couldn't he have been shacking?
couldn't we have been shacking?
couldn't you have been shacking?
couldn't they have been shacking?