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 can't sag you can't sag he can't sag we can't sag you can't sag they can't sag
V-ing form
I can't be sagging you can't be sagging he can't be sagging we can't be sagging you can't be sagging they can't be sagging
Perfect
I can't have sagged you can't have sagged he can't have sagged we can't have sagged you can't have sagged they can't have sagged
V-ing perfect
I can't have been sagging you can't have been sagging he can't have been sagging we can't have been sagging you can't have been sagging they can't 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't I sag? can't you sag? can't he sag? can't we sag? can't you sag? can't they sag?
V-ing form
can't I be sagging? can't you be sagging? can't he be sagging? can't we be sagging? can't you be sagging? can't they be sagging?
Perfect
can't I have sagged? can't you have sagged? can't he have sagged? can't we have sagged? can't you have sagged? can't they have sagged?
V-ing perfect
can't I have been sagging? can't you have been sagging? can't he have been sagging? can't we have been sagging? can't you have been sagging? can't they have been sagging?