I can sack you can sack she can sack we can sack you can sack they can sack
V-ing form
I can be sacking you can be sacking she can be sacking we can be sacking you can be sacking they can be sacking
Perfect
I can have sacked you can have sacked she can have sacked we can have sacked you can have sacked they can have sacked
V-ing perfect
I can have been sacking you can have been sacking she can have been sacking we can have been sacking you can have been sacking they can have been sacking
Negation
Simple form
I cannot sack you cannot sack she cannot sack we cannot sack you cannot sack they cannot sack
V-ing form
I cannot be sacking you cannot be sacking she cannot be sacking we cannot be sacking you cannot be sacking they cannot be sacking
Perfect
I cannot have sacked you cannot have sacked she cannot have sacked we cannot have sacked you cannot have sacked they cannot have sacked
V-ing perfect
I cannot have been sacking you cannot have been sacking she cannot have been sacking we cannot have been sacking you cannot have been sacking they cannot have been sacking
Interrogative form
Simple form
can I sack? can you sack? can she sack? can we sack? can you sack? can they sack?
V-ing form
can I be sacking? can you be sacking? can she be sacking? can we be sacking? can you be sacking? can they be sacking?
Perfect
can I have sacked? can you have sacked? can she have sacked? can we have sacked? can you have sacked? can they have sacked?
V-ing perfect
can I have been sacking? can you have been sacking? can she have been sacking? can we have been sacking? can you have been sacking? can they have been sacking?
Interro-negative form
Simple form
can I not sack? can you not sack? can she not sack? can we not sack? can you not sack? can they not sack?
V-ing form
can I not be sacking? can you not be sacking? can she not be sacking? can we not be sacking? can you not be sacking? can they not be sacking?
Perfect
can I not have sacked? can you not have sacked? can she not have sacked? can we not have sacked? can you not have sacked? can they not have sacked?
V-ing perfect
can I not have been sacking? can you not have been sacking? can she not have been sacking? can we not have been sacking? can you not have been sacking? can they not have been sacking?