English verb conjugation
MUST TUBE

Regular verb: tube - tubed - tubed

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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