English verb conjugation
MUST SICKEN

Regular verb: sicken - sickened - sickened

Affirmation

Simple form	V-ing form
I must sicken you must sicken he must sicken we must sicken you must sicken they must sicken	I must be sickening you must be sickening he must be sickening we must be sickening you must be sickening they must be sickening
Perfect	V-ing perfect
I must have sickened you must have sickened he must have sickened we must have sickened you must have sickened they must have sickened	I must have been sickening you must have been sickening he must have been sickening we must have been sickening you must have been sickening they must have been sickening

Negation

Simple form	V-ing form
I must not sicken you must not sicken he must not sicken we must not sicken you must not sicken they must not sicken	I must not be sickening you must not be sickening he must not be sickening we must not be sickening you must not be sickening they must not be sickening
Perfect	V-ing perfect
I must not have sickened you must not have sickened he must not have sickened we must not have sickened you must not have sickened they must not have sickened	I must not have been sickening you must not have been sickening he must not have been sickening we must not have been sickening you must not have been sickening they must not have been sickening

Interrogative form

Simple form	V-ing form
must I sicken? must you sicken? must he sicken? must we sicken? must you sicken? must they sicken?	must I be sickening? must you be sickening? must he be sickening? must we be sickening? must you be sickening? must they be sickening?
Perfect	V-ing perfect
must I have sickened? must you have sickened? must he have sickened? must we have sickened? must you have sickened? must they have sickened?	must I have been sickening? must you have been sickening? must he have been sickening? must we have been sickening? must you have been sickening? must they have been sickening?

Interro-negative form

Simple form	V-ing form
must I not sicken? must you not sicken? must he not sicken? must we not sicken? must you not sicken? must they not sicken?	must I not be sickening? must you not be sickening? must he not be sickening? must we not be sickening? must you not be sickening? must they not be sickening?
Perfect	V-ing perfect
must I not have sickened? must you not have sickened? must he not have sickened? must we not have sickened? must you not have sickened? must they not have sickened?	must I not have been sickening? must you not have been sickening? must he not have been sickening? must we not have been sickening? must you not have been sickening? must they not have been sickening?