I could drown you could drown she could drown we could drown you could drown they could drown
V-ing form
I could be drowning you could be drowning she could be drowning we could be drowning you could be drowning they could be drowning
Perfect
I could have drowned you could have drowned she could have drowned we could have drowned you could have drowned they could have drowned
V-ing perfect
I could have been drowning you could have been drowning she could have been drowning we could have been drowning you could have been drowning they could have been drowning
Negation
Simple form
I could not drown you could not drown she could not drown we could not drown you could not drown they could not drown
V-ing form
I could not be drowning you could not be drowning she could not be drowning we could not be drowning you could not be drowning they could not be drowning
Perfect
I could not have drowned you could not have drowned she could not have drowned we could not have drowned you could not have drowned they could not have drowned
V-ing perfect
I could not have been drowning you could not have been drowning she could not have been drowning we could not have been drowning you could not have been drowning they could not have been drowning
Interrogative form
Simple form
could I drown? could you drown? could she drown? could we drown? could you drown? could they drown?
V-ing form
could I be drowning? could you be drowning? could she be drowning? could we be drowning? could you be drowning? could they be drowning?
Perfect
could I have drowned? could you have drowned? could she have drowned? could we have drowned? could you have drowned? could they have drowned?
V-ing perfect
could I have been drowning? could you have been drowning? could she have been drowning? could we have been drowning? could you have been drowning? could they have been drowning?
Interro-negative form
Simple form
could I not drown? could you not drown? could she not drown? could we not drown? could you not drown? could they not drown?
V-ing form
could I not be drowning? could you not be drowning? could she not be drowning? could we not be drowning? could you not be drowning? could they not be drowning?
Perfect
could I not have drowned? could you not have drowned? could she not have drowned? could we not have drowned? could you not have drowned? could they not have drowned?
V-ing perfect
could I not have been drowning? could you not have been drowning? could she not have been drowning? could we not have been drowning? could you not have been drowning? could they not have been drowning?