I could brevet you could brevet she could brevet we could brevet you could brevet they could brevet
V-ing form
I could be breveting you could be breveting she could be breveting we could be breveting you could be breveting they could be breveting
Perfect
I could have breveted you could have breveted she 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 she 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 she 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 she 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 she 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 she 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 she brevet? could we brevet? could you brevet? could they brevet?
V-ing form
could I be breveting? could you be breveting? could she be breveting? could we be breveting? could you be breveting? could they be breveting?
Perfect
could I have breveted? could you have breveted? could she 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 she 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 she 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 she 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 she 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 she have been breveting? couldn't we have been breveting? couldn't you have been breveting? couldn't they have been breveting?