I could try you could try she could try we could try you could try they could try
Forma con V-ing
I could be trying you could be trying she could be trying we could be trying you could be trying they could be trying
Perfecto
I could have tried you could have tried she could have tried we could have tried you could have tried they could have tried
Perfecto con V-ing
I could have been trying you could have been trying she could have been trying we could have been trying you could have been trying they could have been trying
Negación
Forma simple
I could not try you could not try she could not try we could not try you could not try they could not try
Forma con V-ing
I could not be trying you could not be trying she could not be trying we could not be trying you could not be trying they could not be trying
Perfecto
I could not have tried you could not have tried she could not have tried we could not have tried you could not have tried they could not have tried
Perfecto con V-ing
I could not have been trying you could not have been trying she could not have been trying we could not have been trying you could not have been trying they could not have been trying
Forma interrogativa
Forma simple
could I try? could you try? could she try? could we try? could you try? could they try?
Forma con V-ing
could I be trying? could you be trying? could she be trying? could we be trying? could you be trying? could they be trying?
Perfecto
could I have tried? could you have tried? could she have tried? could we have tried? could you have tried? could they have tried?
Perfecto con V-ing
could I have been trying? could you have been trying? could she have been trying? could we have been trying? could you have been trying? could they have been trying?
Forma interro-negativa
Forma simple
could I not try? could you not try? could she not try? could we not try? could you not try? could they not try?
Forma con V-ing
could I not be trying? could you not be trying? could she not be trying? could we not be trying? could you not be trying? could they not be trying?
Perfecto
could I not have tried? could you not have tried? could she not have tried? could we not have tried? could you not have tried? could they not have tried?
Perfecto con V-ing
could I not have been trying? could you not have been trying? could she not have been trying? could we not have been trying? could you not have been trying? could they not have been trying?