must twin
Regular verb: twin - twinned- twinned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must twin
you must twin
she must twin
we must twin
you must twin
they must twin 	I must be twinning
you must be twinning
she must be twinning
we must be twinning
you must be twinning
they must be twinning	I must have twinned
you must have twinned
she must have twinned
we must have twinned
you must have twinned
they must have twinned	I must have been twinning
you must have been twinning
she must have been twinning
we must have been twinning
you must have been twinning
they must have been twinning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't twin
you mustn't twin
she mustn't twin
we mustn't twin
you mustn't twin
they mustn't twin 	I mustn't be twinning
you mustn't be twinning
she mustn't be twinning
we mustn't be twinning
you mustn't be twinning
they mustn't be twinning	I mustn't have twinned
you mustn't have twinned
she mustn't have twinned
we mustn't have twinned
you mustn't have twinned
they mustn't have twinned	I mustn't have been twinning
you mustn't have been twinning
she mustn't have been twinning
we mustn't have been twinning
you mustn't have been twinning
they mustn't have been twinning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I twin?
must you twin?
must she twin?
must we twin?
must you twin?
must they twin? 	must I be twinning?
must you be twinning?
must she be twinning?
must we be twinning?
must you be twinning?
must they be twinning? 	must I have twinned?
must you have twinned?
must she have twinned?
must we have twinned?
must you have twinned?
must they have twinned? 	must I have been twinning?
must you have been twinning?
must she have been twinning?
must we have been twinning?
must you have been twinning?
must they have been twinning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I twin?
mustn't you twin?
mustn't she twin?
mustn't we twin?
mustn't you twin?
mustn't they twin? 	mustn't I be twinning?
mustn't you be twinning?
mustn't she be twinning?
mustn't we be twinning?
mustn't you be twinning?
mustn't they be twinning? 	mustn't I have twinned?
mustn't you have twinned?
mustn't she have twinned?
mustn't we have twinned?
mustn't you have twinned?
mustn't they have twinned? 	mustn't I have been twinning?
mustn't you have been twinning?
mustn't she have been twinning?
mustn't we have been twinning?
mustn't you have been twinning?
mustn't they have been twinning?