I could brown you could brown he could brown we could brown you could brown they could brown
V-ing form
I could be browning you could be browning he could be browning we could be browning you could be browning they could be browning
Perfect
I could have browned you could have browned he 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 he 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 he 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 he 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 he 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 he 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 he brown? could we brown? could you brown? could they brown?
V-ing form
could I be browning? could you be browning? could he be browning? could we be browning? could you be browning? could they be browning?
Perfect
could I have browned? could you have browned? could he 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 he 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 he 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 he 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 he 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 he have been browning? couldn't we have been browning? couldn't you have been browning? couldn't they have been browning?