could restack
Regular verb: restack - restacked- restacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could restack
you could restack
she could restack
we could restack
you could restack
they could restack 	I could be restacking
you could be restacking
she could be restacking
we could be restacking
you could be restacking
they could be restacking	I could have restacked
you could have restacked
she could have restacked
we could have restacked
you could have restacked
they could have restacked	I could have been restacking
you could have been restacking
she could have been restacking
we could have been restacking
you could have been restacking
they could have been restacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't restack
you couldn't restack
she couldn't restack
we couldn't restack
you couldn't restack
they couldn't restack 	I couldn't be restacking
you couldn't be restacking
she couldn't be restacking
we couldn't be restacking
you couldn't be restacking
they couldn't be restacking	I couldn't have restacked
you couldn't have restacked
she couldn't have restacked
we couldn't have restacked
you couldn't have restacked
they couldn't have restacked	I couldn't have been restacking
you couldn't have been restacking
she couldn't have been restacking
we couldn't have been restacking
you couldn't have been restacking
they couldn't have been restacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I restack?
could you restack?
could she restack?
could we restack?
could you restack?
could they restack? 	could I be restacking?
could you be restacking?
could she be restacking?
could we be restacking?
could you be restacking?
could they be restacking? 	could I have restacked?
could you have restacked?
could she have restacked?
could we have restacked?
could you have restacked?
could they have restacked? 	could I have been restacking?
could you have been restacking?
could she have been restacking?
could we have been restacking?
could you have been restacking?
could they have been restacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I restack?
couldn't you restack?
couldn't she restack?
couldn't we restack?
couldn't you restack?
couldn't they restack? 	couldn't I be restacking?
couldn't you be restacking?
couldn't she be restacking?
couldn't we be restacking?
couldn't you be restacking?
couldn't they be restacking? 	couldn't I have restacked?
couldn't you have restacked?
couldn't she have restacked?
couldn't we have restacked?
couldn't you have restacked?
couldn't they have restacked? 	couldn't I have been restacking?
couldn't you have been restacking?
couldn't she have been restacking?
couldn't we have been restacking?
couldn't you have been restacking?
couldn't they have been restacking?