must frock
Regular verb: frock - frocked- frocked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must frock
you must frock
she must frock
we must frock
you must frock
they must frock 	I must be frocking
you must be frocking
she must be frocking
we must be frocking
you must be frocking
they must be frocking	I must have frocked
you must have frocked
she must have frocked
we must have frocked
you must have frocked
they must have frocked	I must have been frocking
you must have been frocking
she must have been frocking
we must have been frocking
you must have been frocking
they must have been frocking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not frock
you must not frock
she must not frock
we must not frock
you must not frock
they must not frock 	I must not be frocking
you must not be frocking
she must not be frocking
we must not be frocking
you must not be frocking
they must not be frocking	I must not have frocked
you must not have frocked
she must not have frocked
we must not have frocked
you must not have frocked
they must not have frocked	I must not have been frocking
you must not have been frocking
she must not have been frocking
we must not have been frocking
you must not have been frocking
they must not have been frocking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I frock?
must you frock?
must she frock?
must we frock?
must you frock?
must they frock? 	must I be frocking?
must you be frocking?
must she be frocking?
must we be frocking?
must you be frocking?
must they be frocking? 	must I have frocked?
must you have frocked?
must she have frocked?
must we have frocked?
must you have frocked?
must they have frocked? 	must I have been frocking?
must you have been frocking?
must she have been frocking?
must we have been frocking?
must you have been frocking?
must they have been frocking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not frock?
must you not frock?
must she not frock?
must we not frock?
must you not frock?
must they not frock? 	must I not be frocking?
must you not be frocking?
must she not be frocking?
must we not be frocking?
must you not be frocking?
must they not be frocking? 	must I not have frocked?
must you not have frocked?
must she not have frocked?
must we not have frocked?
must you not have frocked?
must they not have frocked? 	must I not have been frocking?
must you not have been frocking?
must she not have been frocking?
must we not have been frocking?
must you not have been frocking?
must they not have been frocking?