English verb conjugation
CAN HEAD

Regular verb: head - headed - headed

Affirmation

Simple form	V-ing form
I can head you can head he can head we can head you can head they can head	I can be heading you can be heading he can be heading we can be heading you can be heading they can be heading
Perfect	V-ing perfect
I can have headed you can have headed he can have headed we can have headed you can have headed they can have headed	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

Negation

Simple form	V-ing form
I cannot head you cannot head he cannot head we cannot head you cannot head they cannot head	I cannot be heading you cannot be heading he cannot be heading we cannot be heading you cannot be heading they cannot be heading
Perfect	V-ing perfect
I cannot have headed you cannot have headed he cannot have headed we cannot have headed you cannot have headed they cannot have headed	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

Interrogative form

Simple form	V-ing form
can I head? can you head? can he head? can we head? can you head? can they head?	can I be heading? can you be heading? can he be heading? can we be heading? can you be heading? can they be heading?
Perfect	V-ing perfect
can I have headed? can you have headed? can he have headed? can we have headed? can you have headed? can they have headed?	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?

Interro-negative form

Simple form	V-ing form
can I not head? can you not head? can he not head? can we not head? can you not head? can they not head?	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?
Perfect	V-ing perfect
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?	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?