I can head you can head he can head we can head you can head they can head
Forma con V-ing
I can be heading you can be heading he can be heading we can be heading you can be heading they can be heading
Perfecto
I can have headed you can have headed he can have headed we can have headed you can have headed they can have headed
Perfecto con V-ing
I can have been heading you can have been heading he can have been heading we can have been heading you can have been heading they can have been heading
Negación
Forma simple
I cannot head you cannot head he cannot head we cannot head you cannot head they cannot head
Forma con V-ing
I cannot be heading you cannot be heading he cannot be heading we cannot be heading you cannot be heading they cannot be heading
Perfecto
I cannot have headed you cannot have headed he cannot have headed we cannot have headed you cannot have headed they cannot have headed
Perfecto con V-ing
I cannot have been heading you cannot have been heading he cannot have been heading we cannot have been heading you cannot have been heading they cannot have been heading
Forma interrogativa
Forma simple
can I head? can you head? can he head? can we head? can you head? can they head?
Forma con V-ing
can I be heading? can you be heading? can he be heading? can we be heading? can you be heading? can they be heading?
Perfecto
can I have headed? can you have headed? can he have headed? can we have headed? can you have headed? can they have headed?
Perfecto con V-ing
can I have been heading? can you have been heading? can he have been heading? can we have been heading? can you have been heading? can they have been heading?
Forma interro-negativa
Forma simple
can I not head? can you not head? can he not head? can we not head? can you not head? can they not head?
Forma con V-ing
can I not be heading? can you not be heading? can he not be heading? can we not be heading? can you not be heading? can they not be heading?
Perfecto
can I not have headed? can you not have headed? can he not have headed? can we not have headed? can you not have headed? can they not have headed?
Perfecto con V-ing
can I not have been heading? can you not have been heading? can he not have been heading? can we not have been heading? can you not have been heading? can they not have been heading?