I could bur you could bur she could bur we could bur you could bur they could bur
Forma con V-ing
I could be buring you could be buring she could be buring we could be buring you could be buring they could be buring
Perfecto
I could have bured you could have bured she could have bured we could have bured you could have bured they could have bured
Perfecto con V-ing
I could have been buring you could have been buring she could have been buring we could have been buring you could have been buring they could have been buring
Negación
Forma simple
I could not bur you could not bur she could not bur we could not bur you could not bur they could not bur
Forma con V-ing
I could not be buring you could not be buring she could not be buring we could not be buring you could not be buring they could not be buring
Perfecto
I could not have bured you could not have bured she could not have bured we could not have bured you could not have bured they could not have bured
Perfecto con V-ing
I could not have been buring you could not have been buring she could not have been buring we could not have been buring you could not have been buring they could not have been buring
Forma interrogativa
Forma simple
could I bur? could you bur? could she bur? could we bur? could you bur? could they bur?
Forma con V-ing
could I be buring? could you be buring? could she be buring? could we be buring? could you be buring? could they be buring?
Perfecto
could I have bured? could you have bured? could she have bured? could we have bured? could you have bured? could they have bured?
Perfecto con V-ing
could I have been buring? could you have been buring? could she have been buring? could we have been buring? could you have been buring? could they have been buring?
Forma interro-negativa
Forma simple
could I not bur? could you not bur? could she not bur? could we not bur? could you not bur? could they not bur?
Forma con V-ing
could I not be buring? could you not be buring? could she not be buring? could we not be buring? could you not be buring? could they not be buring?
Perfecto
could I not have bured? could you not have bured? could she not have bured? could we not have bured? could you not have bured? could they not have bured?
Perfecto con V-ing
could I not have been buring? could you not have been buring? could she not have been buring? could we not have been buring? could you not have been buring? could they not have been buring?