must fife
Regular verb: fife - fifed- fifed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't fife
you mustn't fife
he mustn't fife
we mustn't fife
you mustn't fife
they mustn't fife 	I mustn't be fifing
you mustn't be fifing
he mustn't be fifing
we mustn't be fifing
you mustn't be fifing
they mustn't be fifing	I mustn't have fifed
you mustn't have fifed
he mustn't have fifed
we mustn't have fifed
you mustn't have fifed
they mustn't have fifed	I mustn't have been fifing
you mustn't have been fifing
he mustn't have been fifing
we mustn't have been fifing
you mustn't have been fifing
they mustn't have been fifing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I fife?
mustn't you fife?
mustn't he fife?
mustn't we fife?
mustn't you fife?
mustn't they fife? 	mustn't I be fifing?
mustn't you be fifing?
mustn't he be fifing?
mustn't we be fifing?
mustn't you be fifing?
mustn't they be fifing? 	mustn't I have fifed?
mustn't you have fifed?
mustn't he have fifed?
mustn't we have fifed?
mustn't you have fifed?
mustn't they have fifed? 	mustn't I have been fifing?
mustn't you have been fifing?
mustn't he have been fifing?
mustn't we have been fifing?
mustn't you have been fifing?
mustn't they have been fifing?