I can ski you can ski he can ski we can ski you can ski they can ski
Forma con V-ing
I can be skiing you can be skiing he can be skiing we can be skiing you can be skiing they can be skiing
Perfecto
I can have skied you can have skied he can have skied we can have skied you can have skied they can have skied
Perfecto con V-ing
I can have been skiing you can have been skiing he can have been skiing we can have been skiing you can have been skiing they can have been skiing
Negación
Forma simple
I can't ski you can't ski he can't ski we can't ski you can't ski they can't ski
Forma con V-ing
I can't be skiing you can't be skiing he can't be skiing we can't be skiing you can't be skiing they can't be skiing
Perfecto
I can't have skied you can't have skied he can't have skied we can't have skied you can't have skied they can't have skied
Perfecto con V-ing
I can't have been skiing you can't have been skiing he can't have been skiing we can't have been skiing you can't have been skiing they can't have been skiing
Forma interrogativa
Forma simple
can I ski? can you ski? can he ski? can we ski? can you ski? can they ski?
Forma con V-ing
can I be skiing? can you be skiing? can he be skiing? can we be skiing? can you be skiing? can they be skiing?
Perfecto
can I have skied? can you have skied? can he have skied? can we have skied? can you have skied? can they have skied?
Perfecto con V-ing
can I have been skiing? can you have been skiing? can he have been skiing? can we have been skiing? can you have been skiing? can they have been skiing?
Forma interro-negativa
Forma simple
can't I ski? can't you ski? can't he ski? can't we ski? can't you ski? can't they ski?
Forma con V-ing
can't I be skiing? can't you be skiing? can't he be skiing? can't we be skiing? can't you be skiing? can't they be skiing?
Perfecto
can't I have skied? can't you have skied? can't he have skied? can't we have skied? can't you have skied? can't they have skied?
Perfecto con V-ing
can't I have been skiing? can't you have been skiing? can't he have been skiing? can't we have been skiing? can't you have been skiing? can't they have been skiing?