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 must not perturb you must not perturb he must not perturb we must not perturb you must not perturb they must not perturb	I must not be perturbing you must not be perturbing he must not be perturbing we must not be perturbing you must not be perturbing they must not be perturbing
Perfect	V-ing perfect
I must not have perturbed you must not have perturbed he must not have perturbed we must not have perturbed you must not have perturbed they must not have perturbed	I must not have been perturbing you must not have been perturbing he must not have been perturbing we must not have been perturbing you must not have been perturbing they must not 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
must I not perturb? must you not perturb? must he not perturb? must we not perturb? must you not perturb? must they not perturb?	must I not be perturbing? must you not be perturbing? must he not be perturbing? must we not be perturbing? must you not be perturbing? must they not be perturbing?
Perfect	V-ing perfect
must I not have perturbed? must you not have perturbed? must he not have perturbed? must we not have perturbed? must you not have perturbed? must they not have perturbed?	must I not have been perturbing? must you not have been perturbing? must he not have been perturbing? must we not have been perturbing? must you not have been perturbing? must they not have been perturbing?