must sing
Verbo irregolare: sing - sang- sung

Affermazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I must sing
you must sing
he must sing
we must sing
you must sing
they must sing 	I must be singing
you must be singing
he must be singing
we must be singing
you must be singing
they must be singing	I must have sung
you must have sung
he must have sung
we must have sung
you must have sung
they must have sung	I must have been singing
you must have been singing
he must have been singing
we must have been singing
you must have been singing
they must have been singing	

Negazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I mustn't sing
you mustn't sing
he mustn't sing
we mustn't sing
you mustn't sing
they mustn't sing 	I mustn't be singing
you mustn't be singing
he mustn't be singing
we mustn't be singing
you mustn't be singing
they mustn't be singing	I mustn't have sung
you mustn't have sung
he mustn't have sung
we mustn't have sung
you mustn't have sung
they mustn't have sung	I mustn't have been singing
you mustn't have been singing
he mustn't have been singing
we mustn't have been singing
you mustn't have been singing
they mustn't have been singing	

Forma interrogativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
must I sing?
must you sing?
must he sing?
must we sing?
must you sing?
must they sing? 	must I be singing?
must you be singing?
must he be singing?
must we be singing?
must you be singing?
must they be singing? 	must I have sung?
must you have sung?
must he have sung?
must we have sung?
must you have sung?
must they have sung? 	must I have been singing?
must you have been singing?
must he have been singing?
must we have been singing?
must you have been singing?
must they have been singing? 	

Forma interro-negativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
mustn't I sing?
mustn't you sing?
mustn't he sing?
mustn't we sing?
mustn't you sing?
mustn't they sing? 	mustn't I be singing?
mustn't you be singing?
mustn't he be singing?
mustn't we be singing?
mustn't you be singing?
mustn't they be singing? 	mustn't I have sung?
mustn't you have sung?
mustn't he have sung?
mustn't we have sung?
mustn't you have sung?
mustn't they have sung? 	mustn't I have been singing?
mustn't you have been singing?
mustn't he have been singing?
mustn't we have been singing?
mustn't you have been singing?
mustn't they have been singing?