English verb conjugation
MUST RUB

Regular verb: rub - rubbed - rubbed

Affirmation

Simple form	V-ing form
I must rub you must rub he must rub we must rub you must rub they must rub	I must be rubbing you must be rubbing he must be rubbing we must be rubbing you must be rubbing they must be rubbing
Perfect	V-ing perfect
I must have rubbed you must have rubbed he must have rubbed we must have rubbed you must have rubbed they must have rubbed	I must have been rubbing you must have been rubbing he must have been rubbing we must have been rubbing you must have been rubbing they must have been rubbing

Negation

Simple form	V-ing form
I must not rub you must not rub he must not rub we must not rub you must not rub they must not rub	I must not be rubbing you must not be rubbing he must not be rubbing we must not be rubbing you must not be rubbing they must not be rubbing
Perfect	V-ing perfect
I must not have rubbed you must not have rubbed he must not have rubbed we must not have rubbed you must not have rubbed they must not have rubbed	I must not have been rubbing you must not have been rubbing he must not have been rubbing we must not have been rubbing you must not have been rubbing they must not have been rubbing

Interrogative form

Simple form	V-ing form
must I rub? must you rub? must he rub? must we rub? must you rub? must they rub?	must I be rubbing? must you be rubbing? must he be rubbing? must we be rubbing? must you be rubbing? must they be rubbing?
Perfect	V-ing perfect
must I have rubbed? must you have rubbed? must he have rubbed? must we have rubbed? must you have rubbed? must they have rubbed?	must I have been rubbing? must you have been rubbing? must he have been rubbing? must we have been rubbing? must you have been rubbing? must they have been rubbing?

Interro-negative form

Simple form	V-ing form
must I not rub? must you not rub? must he not rub? must we not rub? must you not rub? must they not rub?	must I not be rubbing? must you not be rubbing? must he not be rubbing? must we not be rubbing? must you not be rubbing? must they not be rubbing?
Perfect	V-ing perfect
must I not have rubbed? must you not have rubbed? must he not have rubbed? must we not have rubbed? must you not have rubbed? must they not have rubbed?	must I not have been rubbing? must you not have been rubbing? must he not have been rubbing? must we not have been rubbing? must you not have been rubbing? must they not have been rubbing?