must fret
Verbo regular: fret - fretted- fretted

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must fret
you must fret
he must fret
we must fret
you must fret
they must fret 	I must be fretting
you must be fretting
he must be fretting
we must be fretting
you must be fretting
they must be fretting	I must have fretted
you must have fretted
he must have fretted
we must have fretted
you must have fretted
they must have fretted	I must have been fretting
you must have been fretting
he must have been fretting
we must have been fretting
you must have been fretting
they must have been fretting	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not fret
you must not fret
he must not fret
we must not fret
you must not fret
they must not fret 	I must not be fretting
you must not be fretting
he must not be fretting
we must not be fretting
you must not be fretting
they must not be fretting	I must not have fretted
you must not have fretted
he must not have fretted
we must not have fretted
you must not have fretted
they must not have fretted	I must not have been fretting
you must not have been fretting
he must not have been fretting
we must not have been fretting
you must not have been fretting
they must not have been fretting	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I fret?
must you fret?
must he fret?
must we fret?
must you fret?
must they fret? 	must I be fretting?
must you be fretting?
must he be fretting?
must we be fretting?
must you be fretting?
must they be fretting? 	must I have fretted?
must you have fretted?
must he have fretted?
must we have fretted?
must you have fretted?
must they have fretted? 	must I have been fretting?
must you have been fretting?
must he have been fretting?
must we have been fretting?
must you have been fretting?
must they have been fretting? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not fret?
must you not fret?
must he not fret?
must we not fret?
must you not fret?
must they not fret? 	must I not be fretting?
must you not be fretting?
must he not be fretting?
must we not be fretting?
must you not be fretting?
must they not be fretting? 	must I not have fretted?
must you not have fretted?
must he not have fretted?
must we not have fretted?
must you not have fretted?
must they not have fretted? 	must I not have been fretting?
must you not have been fretting?
must he not have been fretting?
must we not have been fretting?
must you not have been fretting?
must they not have been fretting?