English verb conjugation
MUST SKI

Regular verb: ski - skied - skied

Affirmation

Simple form	V-ing form
I must ski you must ski he must ski we must ski you must ski they must ski	I must be skiing you must be skiing he must be skiing we must be skiing you must be skiing they must be skiing
Perfect	V-ing perfect
I must have skied you must have skied he must have skied we must have skied you must have skied they must have skied	I must have been skiing you must have been skiing he must have been skiing we must have been skiing you must have been skiing they must have been skiing

Negation

Simple form	V-ing form
I must not ski you must not ski he must not ski we must not ski you must not ski they must not ski	I must not be skiing you must not be skiing he must not be skiing we must not be skiing you must not be skiing they must not be skiing
Perfect	V-ing perfect
I must not have skied you must not have skied he must not have skied we must not have skied you must not have skied they must not have skied	I must not have been skiing you must not have been skiing he must not have been skiing we must not have been skiing you must not have been skiing they must not have been skiing

Interrogative form

Simple form	V-ing form
must I ski? must you ski? must he ski? must we ski? must you ski? must they ski?	must I be skiing? must you be skiing? must he be skiing? must we be skiing? must you be skiing? must they be skiing?
Perfect	V-ing perfect
must I have skied? must you have skied? must he have skied? must we have skied? must you have skied? must they have skied?	must I have been skiing? must you have been skiing? must he have been skiing? must we have been skiing? must you have been skiing? must they have been skiing?

Interro-negative form

Simple form	V-ing form
must I not ski? must you not ski? must he not ski? must we not ski? must you not ski? must they not ski?	must I not be skiing? must you not be skiing? must he not be skiing? must we not be skiing? must you not be skiing? must they not be skiing?
Perfect	V-ing perfect
must I not have skied? must you not have skied? must he not have skied? must we not have skied? must you not have skied? must they not have skied?	must I not have been skiing? must you not have been skiing? must he not have been skiing? must we not have been skiing? must you not have been skiing? must they not have been skiing?