I can sag you can sag he can sag we can sag you can sag they can sag
V-ing form
I can be sagging you can be sagging he can be sagging we can be sagging you can be sagging they can be sagging
Perfect
I can have sagged you can have sagged he can have sagged we can have sagged you can have sagged they can have sagged
V-ing perfect
I can have been sagging you can have been sagging he can have been sagging we can have been sagging you can have been sagging they can have been sagging
Negation
Simple form
I cannot sag you cannot sag he cannot sag we cannot sag you cannot sag they cannot sag
V-ing form
I cannot be sagging you cannot be sagging he cannot be sagging we cannot be sagging you cannot be sagging they cannot be sagging
Perfect
I cannot have sagged you cannot have sagged he cannot have sagged we cannot have sagged you cannot have sagged they cannot have sagged
V-ing perfect
I cannot have been sagging you cannot have been sagging he cannot have been sagging we cannot have been sagging you cannot have been sagging they cannot have been sagging
Interrogative form
Simple form
can I sag? can you sag? can he sag? can we sag? can you sag? can they sag?
V-ing form
can I be sagging? can you be sagging? can he be sagging? can we be sagging? can you be sagging? can they be sagging?
Perfect
can I have sagged? can you have sagged? can he have sagged? can we have sagged? can you have sagged? can they have sagged?
V-ing perfect
can I have been sagging? can you have been sagging? can he have been sagging? can we have been sagging? can you have been sagging? can they have been sagging?
Interro-negative form
Simple form
can I not sag? can you not sag? can he not sag? can we not sag? can you not sag? can they not sag?
V-ing form
can I not be sagging? can you not be sagging? can he not be sagging? can we not be sagging? can you not be sagging? can they not be sagging?
Perfect
can I not have sagged? can you not have sagged? can he not have sagged? can we not have sagged? can you not have sagged? can they not have sagged?
V-ing perfect
can I not have been sagging? can you not have been sagging? can he not have been sagging? can we not have been sagging? can you not have been sagging? can they not have been sagging?