must snowball
Verbo regular: snowball - snowballed- snowballed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must snowball
you must snowball
he must snowball
we must snowball
you must snowball
they must snowball 	I must be snowballing
you must be snowballing
he must be snowballing
we must be snowballing
you must be snowballing
they must be snowballing	I must have snowballed
you must have snowballed
he must have snowballed
we must have snowballed
you must have snowballed
they must have snowballed	I must have been snowballing
you must have been snowballing
he must have been snowballing
we must have been snowballing
you must have been snowballing
they must have been snowballing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not snowball
you must not snowball
he must not snowball
we must not snowball
you must not snowball
they must not snowball 	I must not be snowballing
you must not be snowballing
he must not be snowballing
we must not be snowballing
you must not be snowballing
they must not be snowballing	I must not have snowballed
you must not have snowballed
he must not have snowballed
we must not have snowballed
you must not have snowballed
they must not have snowballed	I must not have been snowballing
you must not have been snowballing
he must not have been snowballing
we must not have been snowballing
you must not have been snowballing
they must not have been snowballing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I snowball?
must you snowball?
must he snowball?
must we snowball?
must you snowball?
must they snowball? 	must I be snowballing?
must you be snowballing?
must he be snowballing?
must we be snowballing?
must you be snowballing?
must they be snowballing? 	must I have snowballed?
must you have snowballed?
must he have snowballed?
must we have snowballed?
must you have snowballed?
must they have snowballed? 	must I have been snowballing?
must you have been snowballing?
must he have been snowballing?
must we have been snowballing?
must you have been snowballing?
must they have been snowballing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not snowball?
must you not snowball?
must he not snowball?
must we not snowball?
must you not snowball?
must they not snowball? 	must I not be snowballing?
must you not be snowballing?
must he not be snowballing?
must we not be snowballing?
must you not be snowballing?
must they not be snowballing? 	must I not have snowballed?
must you not have snowballed?
must he not have snowballed?
must we not have snowballed?
must you not have snowballed?
must they not have snowballed? 	must I not have been snowballing?
must you not have been snowballing?
must he not have been snowballing?
must we not have been snowballing?
must you not have been snowballing?
must they not have been snowballing?