I can check you can check he can check we can check you can check they can check
Forma con V-ing
I can be checking you can be checking he can be checking we can be checking you can be checking they can be checking
Perfecto
I can have checked you can have checked he can have checked we can have checked you can have checked they can have checked
Perfecto con V-ing
I can have been checking you can have been checking he can have been checking we can have been checking you can have been checking they can have been checking
Negación
Forma simple
I can't check you can't check he can't check we can't check you can't check they can't check
Forma con V-ing
I can't be checking you can't be checking he can't be checking we can't be checking you can't be checking they can't be checking
Perfecto
I can't have checked you can't have checked he can't have checked we can't have checked you can't have checked they can't have checked
Perfecto con V-ing
I can't have been checking you can't have been checking he can't have been checking we can't have been checking you can't have been checking they can't have been checking
Forma interrogativa
Forma simple
can I check? can you check? can he check? can we check? can you check? can they check?
Forma con V-ing
can I be checking? can you be checking? can he be checking? can we be checking? can you be checking? can they be checking?
Perfecto
can I have checked? can you have checked? can he have checked? can we have checked? can you have checked? can they have checked?
Perfecto con V-ing
can I have been checking? can you have been checking? can he have been checking? can we have been checking? can you have been checking? can they have been checking?
Forma interro-negativa
Forma simple
can't I check? can't you check? can't he check? can't we check? can't you check? can't they check?
Forma con V-ing
can't I be checking? can't you be checking? can't he be checking? can't we be checking? can't you be checking? can't they be checking?
Perfecto
can't I have checked? can't you have checked? can't he have checked? can't we have checked? can't you have checked? can't they have checked?
Perfecto con V-ing
can't I have been checking? can't you have been checking? can't he have been checking? can't we have been checking? can't you have been checking? can't they have been checking?