must shirr
Verbo regular: shirr - shirred- shirred

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must shirr
you must shirr
he must shirr
we must shirr
you must shirr
they must shirr 	I must be shirring
you must be shirring
he must be shirring
we must be shirring
you must be shirring
they must be shirring	I must have shirred
you must have shirred
he must have shirred
we must have shirred
you must have shirred
they must have shirred	I must have been shirring
you must have been shirring
he must have been shirring
we must have been shirring
you must have been shirring
they must have been shirring	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not shirr
you must not shirr
he must not shirr
we must not shirr
you must not shirr
they must not shirr 	I must not be shirring
you must not be shirring
he must not be shirring
we must not be shirring
you must not be shirring
they must not be shirring	I must not have shirred
you must not have shirred
he must not have shirred
we must not have shirred
you must not have shirred
they must not have shirred	I must not have been shirring
you must not have been shirring
he must not have been shirring
we must not have been shirring
you must not have been shirring
they must not have been shirring	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I shirr?
must you shirr?
must he shirr?
must we shirr?
must you shirr?
must they shirr? 	must I be shirring?
must you be shirring?
must he be shirring?
must we be shirring?
must you be shirring?
must they be shirring? 	must I have shirred?
must you have shirred?
must he have shirred?
must we have shirred?
must you have shirred?
must they have shirred? 	must I have been shirring?
must you have been shirring?
must he have been shirring?
must we have been shirring?
must you have been shirring?
must they have been shirring? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not shirr?
must you not shirr?
must he not shirr?
must we not shirr?
must you not shirr?
must they not shirr? 	must I not be shirring?
must you not be shirring?
must he not be shirring?
must we not be shirring?
must you not be shirring?
must they not be shirring? 	must I not have shirred?
must you not have shirred?
must he not have shirred?
must we not have shirred?
must you not have shirred?
must they not have shirred? 	must I not have been shirring?
must you not have been shirring?
must he not have been shirring?
must we not have been shirring?
must you not have been shirring?
must they not have been shirring?