could sack
Regular verb: sack - sacked- sacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could sack
you could sack
he could sack
we could sack
you could sack
they could sack 	I could be sacking
you could be sacking
he could be sacking
we could be sacking
you could be sacking
they could be sacking	I could have sacked
you could have sacked
he could have sacked
we could have sacked
you could have sacked
they could have sacked	I could have been sacking
you could have been sacking
he could have been sacking
we could have been sacking
you could have been sacking
they could have been sacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't sack
you couldn't sack
he couldn't sack
we couldn't sack
you couldn't sack
they couldn't sack 	I couldn't be sacking
you couldn't be sacking
he couldn't be sacking
we couldn't be sacking
you couldn't be sacking
they couldn't be sacking	I couldn't have sacked
you couldn't have sacked
he couldn't have sacked
we couldn't have sacked
you couldn't have sacked
they couldn't have sacked	I couldn't have been sacking
you couldn't have been sacking
he couldn't have been sacking
we couldn't have been sacking
you couldn't have been sacking
they couldn't have been sacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I sack?
could you sack?
could he sack?
could we sack?
could you sack?
could they sack? 	could I be sacking?
could you be sacking?
could he be sacking?
could we be sacking?
could you be sacking?
could they be sacking? 	could I have sacked?
could you have sacked?
could he have sacked?
could we have sacked?
could you have sacked?
could they have sacked? 	could I have been sacking?
could you have been sacking?
could he have been sacking?
could we have been sacking?
could you have been sacking?
could they have been sacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I sack?
couldn't you sack?
couldn't he sack?
couldn't we sack?
couldn't you sack?
couldn't they sack? 	couldn't I be sacking?
couldn't you be sacking?
couldn't he be sacking?
couldn't we be sacking?
couldn't you be sacking?
couldn't they be sacking? 	couldn't I have sacked?
couldn't you have sacked?
couldn't he have sacked?
couldn't we have sacked?
couldn't you have sacked?
couldn't they have sacked? 	couldn't I have been sacking?
couldn't you have been sacking?
couldn't he have been sacking?
couldn't we have been sacking?
couldn't you have been sacking?
couldn't they have been sacking?