must sum
Verbo regolare: sum - summed- summed

Affermazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I must sum
you must sum
she must sum
we must sum
you must sum
they must sum 	I must be summing
you must be summing
she must be summing
we must be summing
you must be summing
they must be summing	I must have summed
you must have summed
she must have summed
we must have summed
you must have summed
they must have summed	I must have been summing
you must have been summing
she must have been summing
we must have been summing
you must have been summing
they must have been summing	

Negazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I mustn't sum
you mustn't sum
she mustn't sum
we mustn't sum
you mustn't sum
they mustn't sum 	I mustn't be summing
you mustn't be summing
she mustn't be summing
we mustn't be summing
you mustn't be summing
they mustn't be summing	I mustn't have summed
you mustn't have summed
she mustn't have summed
we mustn't have summed
you mustn't have summed
they mustn't have summed	I mustn't have been summing
you mustn't have been summing
she mustn't have been summing
we mustn't have been summing
you mustn't have been summing
they mustn't have been summing	

Forma interrogativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
must I sum?
must you sum?
must she sum?
must we sum?
must you sum?
must they sum? 	must I be summing?
must you be summing?
must she be summing?
must we be summing?
must you be summing?
must they be summing? 	must I have summed?
must you have summed?
must she have summed?
must we have summed?
must you have summed?
must they have summed? 	must I have been summing?
must you have been summing?
must she have been summing?
must we have been summing?
must you have been summing?
must they have been summing? 	

Forma interro-negativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
mustn't I sum?
mustn't you sum?
mustn't she sum?
mustn't we sum?
mustn't you sum?
mustn't they sum? 	mustn't I be summing?
mustn't you be summing?
mustn't she be summing?
mustn't we be summing?
mustn't you be summing?
mustn't they be summing? 	mustn't I have summed?
mustn't you have summed?
mustn't she have summed?
mustn't we have summed?
mustn't you have summed?
mustn't they have summed? 	mustn't I have been summing?
mustn't you have been summing?
mustn't she have been summing?
mustn't we have been summing?
mustn't you have been summing?
mustn't they have been summing?