I can check you can check he can check we can check you can check they can check
Forma com 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
Perfeito
I can have checked you can have checked he can have checked we can have checked you can have checked they can have checked
Perfeito com 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
Negação
Forma simple
I cannot check you cannot check he cannot check we cannot check you cannot check they cannot check
Forma com V-ing
I cannot be checking you cannot be checking he cannot be checking we cannot be checking you cannot be checking they cannot be checking
Perfeito
I cannot have checked you cannot have checked he cannot have checked we cannot have checked you cannot have checked they cannot have checked
Perfeito com V-ing
I cannot have been checking you cannot have been checking he cannot have been checking we cannot have been checking you cannot have been checking they cannot 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 com 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?
Perfeito
can I have checked? can you have checked? can he have checked? can we have checked? can you have checked? can they have checked?
Perfeito com 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-Negação
Forma simple
can I not check? can you not check? can he not check? can we not check? can you not check? can they not check?
Forma com V-ing
can I not be checking? can you not be checking? can he not be checking? can we not be checking? can you not be checking? can they not be checking?
Perfeito
can I not have checked? can you not have checked? can he not have checked? can we not have checked? can you not have checked? can they not have checked?
Perfeito com V-ing
can I not have been checking? can you not have been checking? can he not have been checking? can we not have been checking? can you not have been checking? can they not have been checking?