I could be you could be he could be we could be you could be they could be
V-ing form
I could be being you could be being he could be being we could be being you could be being they could be being
Perfect
I could have been you could have been he could have been we could have been you could have been they could have been
V-ing perfect
I could have been being you could have been being he could have been being we could have been being you could have been being they could have been being
Negation
Simple form
I couldn't be you couldn't be he couldn't be we couldn't be you couldn't be they couldn't be
V-ing form
I couldn't be being you couldn't be being he couldn't be being we couldn't be being you couldn't be being they couldn't be being
Perfect
I couldn't have been you couldn't have been he couldn't have been we couldn't have been you couldn't have been they couldn't have been
V-ing perfect
I couldn't have been being you couldn't have been being he couldn't have been being we couldn't have been being you couldn't have been being they couldn't have been being
Interrogative form
Simple form
could I be? could you be? could he be? could we be? could you be? could they be?
V-ing form
could I be being? could you be being? could he be being? could we be being? could you be being? could they be being?
Perfect
could I have been? could you have been? could he have been? could we have been? could you have been? could they have been?
V-ing perfect
could I have been being? could you have been being? could he have been being? could we have been being? could you have been being? could they have been being?
Interro-negative form
Simple form
couldn't I be? couldn't you be? couldn't he be? couldn't we be? couldn't you be? couldn't they be?
V-ing form
couldn't I be being? couldn't you be being? couldn't he be being? couldn't we be being? couldn't you be being? couldn't they be being?
Perfect
couldn't I have been? couldn't you have been? couldn't he have been? couldn't we have been? couldn't you have been? couldn't they have been?
V-ing perfect
couldn't I have been being? couldn't you have been being? couldn't he have been being? couldn't we have been being? couldn't you have been being? couldn't they have been being?