English verb conjugation
CAN TUBE

Regular verb: tube - tubed - tubed

Affirmation

Simple form	V-ing form
I can tube you can tube he can tube we can tube you can tube they can tube	I can be tubing you can be tubing he can be tubing we can be tubing you can be tubing they can be tubing
Perfect	V-ing perfect
I can have tubed you can have tubed he can have tubed we can have tubed you can have tubed they can have tubed	I can have been tubing you can have been tubing he can have been tubing we can have been tubing you can have been tubing they can have been tubing

Negation

Simple form	V-ing form
I cannot tube you cannot tube he cannot tube we cannot tube you cannot tube they cannot tube	I cannot be tubing you cannot be tubing he cannot be tubing we cannot be tubing you cannot be tubing they cannot be tubing
Perfect	V-ing perfect
I cannot have tubed you cannot have tubed he cannot have tubed we cannot have tubed you cannot have tubed they cannot have tubed	I cannot have been tubing you cannot have been tubing he cannot have been tubing we cannot have been tubing you cannot have been tubing they cannot have been tubing

Interrogative form

Simple form	V-ing form
can I tube? can you tube? can he tube? can we tube? can you tube? can they tube?	can I be tubing? can you be tubing? can he be tubing? can we be tubing? can you be tubing? can they be tubing?
Perfect	V-ing perfect
can I have tubed? can you have tubed? can he have tubed? can we have tubed? can you have tubed? can they have tubed?	can I have been tubing? can you have been tubing? can he have been tubing? can we have been tubing? can you have been tubing? can they have been tubing?

Interro-negative form

Simple form	V-ing form
can I not tube? can you not tube? can he not tube? can we not tube? can you not tube? can they not tube?	can I not be tubing? can you not be tubing? can he not be tubing? can we not be tubing? can you not be tubing? can they not be tubing?
Perfect	V-ing perfect
can I not have tubed? can you not have tubed? can he not have tubed? can we not have tubed? can you not have tubed? can they not have tubed?	can I not have been tubing? can you not have been tubing? can he not have been tubing? can we not have been tubing? can you not have been tubing? can they not have been tubing?