must interfile
Regular verb: interfile - interfiled- interfiled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must interfile
you must interfile
she must interfile
we must interfile
you must interfile
they must interfile 	I must be interfiling
you must be interfiling
she must be interfiling
we must be interfiling
you must be interfiling
they must be interfiling	I must have interfiled
you must have interfiled
she must have interfiled
we must have interfiled
you must have interfiled
they must have interfiled	I must have been interfiling
you must have been interfiling
she must have been interfiling
we must have been interfiling
you must have been interfiling
they must have been interfiling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't interfile
you mustn't interfile
she mustn't interfile
we mustn't interfile
you mustn't interfile
they mustn't interfile 	I mustn't be interfiling
you mustn't be interfiling
she mustn't be interfiling
we mustn't be interfiling
you mustn't be interfiling
they mustn't be interfiling	I mustn't have interfiled
you mustn't have interfiled
she mustn't have interfiled
we mustn't have interfiled
you mustn't have interfiled
they mustn't have interfiled	I mustn't have been interfiling
you mustn't have been interfiling
she mustn't have been interfiling
we mustn't have been interfiling
you mustn't have been interfiling
they mustn't have been interfiling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I interfile?
must you interfile?
must she interfile?
must we interfile?
must you interfile?
must they interfile? 	must I be interfiling?
must you be interfiling?
must she be interfiling?
must we be interfiling?
must you be interfiling?
must they be interfiling? 	must I have interfiled?
must you have interfiled?
must she have interfiled?
must we have interfiled?
must you have interfiled?
must they have interfiled? 	must I have been interfiling?
must you have been interfiling?
must she have been interfiling?
must we have been interfiling?
must you have been interfiling?
must they have been interfiling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I interfile?
mustn't you interfile?
mustn't she interfile?
mustn't we interfile?
mustn't you interfile?
mustn't they interfile? 	mustn't I be interfiling?
mustn't you be interfiling?
mustn't she be interfiling?
mustn't we be interfiling?
mustn't you be interfiling?
mustn't they be interfiling? 	mustn't I have interfiled?
mustn't you have interfiled?
mustn't she have interfiled?
mustn't we have interfiled?
mustn't you have interfiled?
mustn't they have interfiled? 	mustn't I have been interfiling?
mustn't you have been interfiling?
mustn't she have been interfiling?
mustn't we have been interfiling?
mustn't you have been interfiling?
mustn't they have been interfiling?