I can sign you can sign he can sign we can sign you can sign they can sign
Forma con V-ing
I can be signing you can be signing he can be signing we can be signing you can be signing they can be signing
Perfecto
I can have signed you can have signed he can have signed we can have signed you can have signed they can have signed
Perfecto con V-ing
I can have been signing you can have been signing he can have been signing we can have been signing you can have been signing they can have been signing
Negación
Forma simple
I can't sign you can't sign he can't sign we can't sign you can't sign they can't sign
Forma con V-ing
I can't be signing you can't be signing he can't be signing we can't be signing you can't be signing they can't be signing
Perfecto
I can't have signed you can't have signed he can't have signed we can't have signed you can't have signed they can't have signed
Perfecto con V-ing
I can't have been signing you can't have been signing he can't have been signing we can't have been signing you can't have been signing they can't have been signing
Forma interrogativa
Forma simple
can I sign? can you sign? can he sign? can we sign? can you sign? can they sign?
Forma con V-ing
can I be signing? can you be signing? can he be signing? can we be signing? can you be signing? can they be signing?
Perfecto
can I have signed? can you have signed? can he have signed? can we have signed? can you have signed? can they have signed?
Perfecto con V-ing
can I have been signing? can you have been signing? can he have been signing? can we have been signing? can you have been signing? can they have been signing?
Forma interro-negativa
Forma simple
can't I sign? can't you sign? can't he sign? can't we sign? can't you sign? can't they sign?
Forma con V-ing
can't I be signing? can't you be signing? can't he be signing? can't we be signing? can't you be signing? can't they be signing?
Perfecto
can't I have signed? can't you have signed? can't he have signed? can't we have signed? can't you have signed? can't they have signed?
Perfecto con V-ing
can't I have been signing? can't you have been signing? can't he have been signing? can't we have been signing? can't you have been signing? can't they have been signing?