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