must span
Verbo regular: span - spanned- spanned

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must span
you must span
he must span
we must span
you must span
they must span 	I must be spanning
you must be spanning
he must be spanning
we must be spanning
you must be spanning
they must be spanning	I must have spanned
you must have spanned
he must have spanned
we must have spanned
you must have spanned
they must have spanned	I must have been spanning
you must have been spanning
he must have been spanning
we must have been spanning
you must have been spanning
they must have been spanning	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't span
you mustn't span
he mustn't span
we mustn't span
you mustn't span
they mustn't span 	I mustn't be spanning
you mustn't be spanning
he mustn't be spanning
we mustn't be spanning
you mustn't be spanning
they mustn't be spanning	I mustn't have spanned
you mustn't have spanned
he mustn't have spanned
we mustn't have spanned
you mustn't have spanned
they mustn't have spanned	I mustn't have been spanning
you mustn't have been spanning
he mustn't have been spanning
we mustn't have been spanning
you mustn't have been spanning
they mustn't have been spanning	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I span?
must you span?
must he span?
must we span?
must you span?
must they span? 	must I be spanning?
must you be spanning?
must he be spanning?
must we be spanning?
must you be spanning?
must they be spanning? 	must I have spanned?
must you have spanned?
must he have spanned?
must we have spanned?
must you have spanned?
must they have spanned? 	must I have been spanning?
must you have been spanning?
must he have been spanning?
must we have been spanning?
must you have been spanning?
must they have been spanning? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I span?
mustn't you span?
mustn't he span?
mustn't we span?
mustn't you span?
mustn't they span? 	mustn't I be spanning?
mustn't you be spanning?
mustn't he be spanning?
mustn't we be spanning?
mustn't you be spanning?
mustn't they be spanning? 	mustn't I have spanned?
mustn't you have spanned?
mustn't he have spanned?
mustn't we have spanned?
mustn't you have spanned?
mustn't they have spanned? 	mustn't I have been spanning?
mustn't you have been spanning?
mustn't he have been spanning?
mustn't we have been spanning?
mustn't you have been spanning?
mustn't they have been spanning?