I must frolic you must frolic she must frolic we must frolic you must frolic they must frolic
V-ing form
I must be frolicing you must be frolicing she must be frolicing we must be frolicing you must be frolicing they must be frolicing
Perfect
I must have froliced you must have froliced she must have froliced we must have froliced you must have froliced they must have froliced
V-ing perfect
I must have been frolicing you must have been frolicing she must have been frolicing we must have been frolicing you must have been frolicing they must have been frolicing
Negation
Simple form
I must not frolic you must not frolic she must not frolic we must not frolic you must not frolic they must not frolic
V-ing form
I must not be frolicing you must not be frolicing she must not be frolicing we must not be frolicing you must not be frolicing they must not be frolicing
Perfect
I must not have froliced you must not have froliced she must not have froliced we must not have froliced you must not have froliced they must not have froliced
V-ing perfect
I must not have been frolicing you must not have been frolicing she must not have been frolicing we must not have been frolicing you must not have been frolicing they must not have been frolicing
Interrogative form
Simple form
must I frolic? must you frolic? must she frolic? must we frolic? must you frolic? must they frolic?
V-ing form
must I be frolicing? must you be frolicing? must she be frolicing? must we be frolicing? must you be frolicing? must they be frolicing?
Perfect
must I have froliced? must you have froliced? must she have froliced? must we have froliced? must you have froliced? must they have froliced?
V-ing perfect
must I have been frolicing? must you have been frolicing? must she have been frolicing? must we have been frolicing? must you have been frolicing? must they have been frolicing?
Interro-negative form
Simple form
must I not frolic? must you not frolic? must she not frolic? must we not frolic? must you not frolic? must they not frolic?
V-ing form
must I not be frolicing? must you not be frolicing? must she not be frolicing? must we not be frolicing? must you not be frolicing? must they not be frolicing?
Perfect
must I not have froliced? must you not have froliced? must she not have froliced? must we not have froliced? must you not have froliced? must they not have froliced?
V-ing perfect
must I not have been frolicing? must you not have been frolicing? must she not have been frolicing? must we not have been frolicing? must you not have been frolicing? must they not have been frolicing?