English verb conjugation
MUST RUB

Regular verb: rub - rubbed - rubbed

Affirmation

Simple form	V-ing form
I must rub you must rub she must rub we must rub you must rub they must rub	I must be rubbing you must be rubbing she 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 she 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 she 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 she 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 she 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 she 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 she 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 she rub? must we rub? must you rub? must they rub?	must I be rubbing? must you be rubbing? must she 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 she 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 she 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 she 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 she 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 she 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 she have been rubbing? mustn't we have been rubbing? mustn't you have been rubbing? mustn't they have been rubbing?