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 must not sum
you must not sum
she must not sum
we must not sum
you must not sum
they must not sum 	I must not be summing
you must not be summing
she must not be summing
we must not be summing
you must not be summing
they must not be summing	I must not have summed
you must not have summed
she must not have summed
we must not have summed
you must not have summed
they must not have summed	I must not have been summing
you must not have been summing
she must not have been summing
we must not have been summing
you must not have been summing
they must not 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 	
must I not sum?
must you not sum?
must she not sum?
must we not sum?
must you not sum?
must they not sum? 	must I not be summing?
must you not be summing?
must she not be summing?
must we not be summing?
must you not be summing?
must they not be summing? 	must I not have summed?
must you not have summed?
must she not have summed?
must we not have summed?
must you not have summed?
must they not have summed? 	must I not have been summing?
must you not have been summing?
must she not have been summing?
must we not have been summing?
must you not have been summing?
must they not have been summing?