must fife
Verbo regular: fife - fifed- fifed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must fife
you must fife
he must fife
we must fife
you must fife
they must fife 	I must be fifing
you must be fifing
he must be fifing
we must be fifing
you must be fifing
they must be fifing	I must have fifed
you must have fifed
he must have fifed
we must have fifed
you must have fifed
they must have fifed	I must have been fifing
you must have been fifing
he must have been fifing
we must have been fifing
you must have been fifing
they must have been fifing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not fife
you must not fife
he must not fife
we must not fife
you must not fife
they must not fife 	I must not be fifing
you must not be fifing
he must not be fifing
we must not be fifing
you must not be fifing
they must not be fifing	I must not have fifed
you must not have fifed
he must not have fifed
we must not have fifed
you must not have fifed
they must not have fifed	I must not have been fifing
you must not have been fifing
he must not have been fifing
we must not have been fifing
you must not have been fifing
they must not have been fifing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I fife?
must you fife?
must he fife?
must we fife?
must you fife?
must they fife? 	must I be fifing?
must you be fifing?
must he be fifing?
must we be fifing?
must you be fifing?
must they be fifing? 	must I have fifed?
must you have fifed?
must he have fifed?
must we have fifed?
must you have fifed?
must they have fifed? 	must I have been fifing?
must you have been fifing?
must he have been fifing?
must we have been fifing?
must you have been fifing?
must they have been fifing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not fife?
must you not fife?
must he not fife?
must we not fife?
must you not fife?
must they not fife? 	must I not be fifing?
must you not be fifing?
must he not be fifing?
must we not be fifing?
must you not be fifing?
must they not be fifing? 	must I not have fifed?
must you not have fifed?
must he not have fifed?
must we not have fifed?
must you not have fifed?
must they not have fifed? 	must I not have been fifing?
must you not have been fifing?
must he not have been fifing?
must we not have been fifing?
must you not have been fifing?
must they not have been fifing?