English verb conjugation
CAN QUARTERBACK

Regular verb: quarterback - quarterbacked - quarterbacked

Affirmation

Simple form	V-ing form
I can quarterback you can quarterback he can quarterback we can quarterback you can quarterback they can quarterback	I can be quarterbacking you can be quarterbacking he can be quarterbacking we can be quarterbacking you can be quarterbacking they can be quarterbacking
Perfect	V-ing perfect
I can have quarterbacked you can have quarterbacked he can have quarterbacked we can have quarterbacked you can have quarterbacked they can have quarterbacked	I can have been quarterbacking you can have been quarterbacking he can have been quarterbacking we can have been quarterbacking you can have been quarterbacking they can have been quarterbacking

Negation

Simple form	V-ing form
I cannot quarterback you cannot quarterback he cannot quarterback we cannot quarterback you cannot quarterback they cannot quarterback	I cannot be quarterbacking you cannot be quarterbacking he cannot be quarterbacking we cannot be quarterbacking you cannot be quarterbacking they cannot be quarterbacking
Perfect	V-ing perfect
I cannot have quarterbacked you cannot have quarterbacked he cannot have quarterbacked we cannot have quarterbacked you cannot have quarterbacked they cannot have quarterbacked	I cannot have been quarterbacking you cannot have been quarterbacking he cannot have been quarterbacking we cannot have been quarterbacking you cannot have been quarterbacking they cannot have been quarterbacking

Interrogative form

Simple form	V-ing form
can I quarterback? can you quarterback? can he quarterback? can we quarterback? can you quarterback? can they quarterback?	can I be quarterbacking? can you be quarterbacking? can he be quarterbacking? can we be quarterbacking? can you be quarterbacking? can they be quarterbacking?
Perfect	V-ing perfect
can I have quarterbacked? can you have quarterbacked? can he have quarterbacked? can we have quarterbacked? can you have quarterbacked? can they have quarterbacked?	can I have been quarterbacking? can you have been quarterbacking? can he have been quarterbacking? can we have been quarterbacking? can you have been quarterbacking? can they have been quarterbacking?

Interro-negative form

Simple form	V-ing form
can I not quarterback? can you not quarterback? can he not quarterback? can we not quarterback? can you not quarterback? can they not quarterback?	can I not be quarterbacking? can you not be quarterbacking? can he not be quarterbacking? can we not be quarterbacking? can you not be quarterbacking? can they not be quarterbacking?
Perfect	V-ing perfect
can I not have quarterbacked? can you not have quarterbacked? can he not have quarterbacked? can we not have quarterbacked? can you not have quarterbacked? can they not have quarterbacked?	can I not have been quarterbacking? can you not have been quarterbacking? can he not have been quarterbacking? can we not have been quarterbacking? can you not have been quarterbacking? can they not have been quarterbacking?