must fuse
Regular verb: fuse - fused- fused

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must fuse
you must fuse
he must fuse
we must fuse
you must fuse
they must fuse 	I must be fusing
you must be fusing
he must be fusing
we must be fusing
you must be fusing
they must be fusing	I must have fused
you must have fused
he must have fused
we must have fused
you must have fused
they must have fused	I must have been fusing
you must have been fusing
he must have been fusing
we must have been fusing
you must have been fusing
they must have been fusing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't fuse
you mustn't fuse
he mustn't fuse
we mustn't fuse
you mustn't fuse
they mustn't fuse 	I mustn't be fusing
you mustn't be fusing
he mustn't be fusing
we mustn't be fusing
you mustn't be fusing
they mustn't be fusing	I mustn't have fused
you mustn't have fused
he mustn't have fused
we mustn't have fused
you mustn't have fused
they mustn't have fused	I mustn't have been fusing
you mustn't have been fusing
he mustn't have been fusing
we mustn't have been fusing
you mustn't have been fusing
they mustn't have been fusing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I fuse?
must you fuse?
must he fuse?
must we fuse?
must you fuse?
must they fuse? 	must I be fusing?
must you be fusing?
must he be fusing?
must we be fusing?
must you be fusing?
must they be fusing? 	must I have fused?
must you have fused?
must he have fused?
must we have fused?
must you have fused?
must they have fused? 	must I have been fusing?
must you have been fusing?
must he have been fusing?
must we have been fusing?
must you have been fusing?
must they have been fusing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I fuse?
mustn't you fuse?
mustn't he fuse?
mustn't we fuse?
mustn't you fuse?
mustn't they fuse? 	mustn't I be fusing?
mustn't you be fusing?
mustn't he be fusing?
mustn't we be fusing?
mustn't you be fusing?
mustn't they be fusing? 	mustn't I have fused?
mustn't you have fused?
mustn't he have fused?
mustn't we have fused?
mustn't you have fused?
mustn't they have fused? 	mustn't I have been fusing?
mustn't you have been fusing?
mustn't he have been fusing?
mustn't we have been fusing?
mustn't you have been fusing?
mustn't they have been fusing?