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