English verb conjugation
MUST PERTURB

Regular verb: perturb - perturbed - perturbed

Affirmation

Simple form	V-ing form
I must perturb you must perturb he must perturb we must perturb you must perturb they must perturb	I must be perturbing you must be perturbing he must be perturbing we must be perturbing you must be perturbing they must be perturbing
Perfect	V-ing perfect
I must have perturbed you must have perturbed he must have perturbed we must have perturbed you must have perturbed they must have perturbed	I must have been perturbing you must have been perturbing he must have been perturbing we must have been perturbing you must have been perturbing they must have been perturbing

Negation

Simple form	V-ing form
I mustn't perturb you mustn't perturb he mustn't perturb we mustn't perturb you mustn't perturb they mustn't perturb	I mustn't be perturbing you mustn't be perturbing he mustn't be perturbing we mustn't be perturbing you mustn't be perturbing they mustn't be perturbing
Perfect	V-ing perfect
I mustn't have perturbed you mustn't have perturbed he mustn't have perturbed we mustn't have perturbed you mustn't have perturbed they mustn't have perturbed	I mustn't have been perturbing you mustn't have been perturbing he mustn't have been perturbing we mustn't have been perturbing you mustn't have been perturbing they mustn't have been perturbing

Interrogative form

Simple form	V-ing form
must I perturb? must you perturb? must he perturb? must we perturb? must you perturb? must they perturb?	must I be perturbing? must you be perturbing? must he be perturbing? must we be perturbing? must you be perturbing? must they be perturbing?
Perfect	V-ing perfect
must I have perturbed? must you have perturbed? must he have perturbed? must we have perturbed? must you have perturbed? must they have perturbed?	must I have been perturbing? must you have been perturbing? must he have been perturbing? must we have been perturbing? must you have been perturbing? must they have been perturbing?

Interro-negative form

Simple form	V-ing form
mustn't I perturb? mustn't you perturb? mustn't he perturb? mustn't we perturb? mustn't you perturb? mustn't they perturb?	mustn't I be perturbing? mustn't you be perturbing? mustn't he be perturbing? mustn't we be perturbing? mustn't you be perturbing? mustn't they be perturbing?
Perfect	V-ing perfect
mustn't I have perturbed? mustn't you have perturbed? mustn't he have perturbed? mustn't we have perturbed? mustn't you have perturbed? mustn't they have perturbed?	mustn't I have been perturbing? mustn't you have been perturbing? mustn't he have been perturbing? mustn't we have been perturbing? mustn't you have been perturbing? mustn't they have been perturbing?