I could march you could march she could march we could march you could march they could march
Forma con V-ing
I could be marching you could be marching she could be marching we could be marching you could be marching they could be marching
Perfecto
I could have marched you could have marched she could have marched we could have marched you could have marched they could have marched
Perfecto con V-ing
I could have been marching you could have been marching she could have been marching we could have been marching you could have been marching they could have been marching
Negación
Forma simple
I could not march you could not march she could not march we could not march you could not march they could not march
Forma con V-ing
I could not be marching you could not be marching she could not be marching we could not be marching you could not be marching they could not be marching
Perfecto
I could not have marched you could not have marched she could not have marched we could not have marched you could not have marched they could not have marched
Perfecto con V-ing
I could not have been marching you could not have been marching she could not have been marching we could not have been marching you could not have been marching they could not have been marching
Forma interrogativa
Forma simple
could I march? could you march? could she march? could we march? could you march? could they march?
Forma con V-ing
could I be marching? could you be marching? could she be marching? could we be marching? could you be marching? could they be marching?
Perfecto
could I have marched? could you have marched? could she have marched? could we have marched? could you have marched? could they have marched?
Perfecto con V-ing
could I have been marching? could you have been marching? could she have been marching? could we have been marching? could you have been marching? could they have been marching?
Forma interro-negativa
Forma simple
could I not march? could you not march? could she not march? could we not march? could you not march? could they not march?
Forma con V-ing
could I not be marching? could you not be marching? could she not be marching? could we not be marching? could you not be marching? could they not be marching?
Perfecto
could I not have marched? could you not have marched? could she not have marched? could we not have marched? could you not have marched? could they not have marched?
Perfecto con V-ing
could I not have been marching? could you not have been marching? could she not have been marching? could we not have been marching? could you not have been marching? could they not have been marching?