I could brown you could brown she could brown we could brown you could brown they could brown
V-ing form
I could be browning you could be browning she could be browning we could be browning you could be browning they could be browning
Perfect
I could have browned you could have browned she could have browned we could have browned you could have browned they could have browned
V-ing perfect
I could have been browning you could have been browning she could have been browning we could have been browning you could have been browning they could have been browning
Negation
Simple form
I couldn't brown you couldn't brown she couldn't brown we couldn't brown you couldn't brown they couldn't brown
V-ing form
I couldn't be browning you couldn't be browning she couldn't be browning we couldn't be browning you couldn't be browning they couldn't be browning
Perfect
I couldn't have browned you couldn't have browned she couldn't have browned we couldn't have browned you couldn't have browned they couldn't have browned
V-ing perfect
I couldn't have been browning you couldn't have been browning she couldn't have been browning we couldn't have been browning you couldn't have been browning they couldn't have been browning
Interrogative form
Simple form
could I brown? could you brown? could she brown? could we brown? could you brown? could they brown?
V-ing form
could I be browning? could you be browning? could she be browning? could we be browning? could you be browning? could they be browning?
Perfect
could I have browned? could you have browned? could she have browned? could we have browned? could you have browned? could they have browned?
V-ing perfect
could I have been browning? could you have been browning? could she have been browning? could we have been browning? could you have been browning? could they have been browning?
Interro-negative form
Simple form
couldn't I brown? couldn't you brown? couldn't she brown? couldn't we brown? couldn't you brown? couldn't they brown?
V-ing form
couldn't I be browning? couldn't you be browning? couldn't she be browning? couldn't we be browning? couldn't you be browning? couldn't they be browning?
Perfect
couldn't I have browned? couldn't you have browned? couldn't she have browned? couldn't we have browned? couldn't you have browned? couldn't they have browned?
V-ing perfect
couldn't I have been browning? couldn't you have been browning? couldn't she have been browning? couldn't we have been browning? couldn't you have been browning? couldn't they have been browning?