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 mustn't rub you mustn't rub he mustn't rub we mustn't rub you mustn't rub they mustn't rub	I mustn't be rubbing you mustn't be rubbing he mustn't be rubbing we mustn't be rubbing you mustn't be rubbing they mustn't be rubbing
Perfect	V-ing perfect
I mustn't have rubbed you mustn't have rubbed he mustn't have rubbed we mustn't have rubbed you mustn't have rubbed they mustn't have rubbed	I mustn't have been rubbing you mustn't have been rubbing he mustn't have been rubbing we mustn't have been rubbing you mustn't have been rubbing they mustn't 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
mustn't I rub? mustn't you rub? mustn't he rub? mustn't we rub? mustn't you rub? mustn't they rub?	mustn't I be rubbing? mustn't you be rubbing? mustn't he be rubbing? mustn't we be rubbing? mustn't you be rubbing? mustn't they be rubbing?
Perfect	V-ing perfect
mustn't I have rubbed? mustn't you have rubbed? mustn't he have rubbed? mustn't we have rubbed? mustn't you have rubbed? mustn't they have rubbed?	mustn't I have been rubbing? mustn't you have been rubbing? mustn't he have been rubbing? mustn't we have been rubbing? mustn't you have been rubbing? mustn't they have been rubbing?