English verb conjugation
MUST SICKEN

Regular verb: sicken - sickened - sickened

Affirmation

Simple form	V-ing form
I must sicken you must sicken she must sicken we must sicken you must sicken they must sicken	I must be sickening you must be sickening she 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 she 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 she 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 she 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 she 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 she 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 she 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 she sicken? must we sicken? must you sicken? must they sicken?	must I be sickening? must you be sickening? must she 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 she 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 she 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 she 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 she 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 she 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 she not have been sickening? must we not have been sickening? must you not have been sickening? must they not have been sickening?