must frost
Verbo regular: frost - frosted- frosted

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must frost
you must frost
he must frost
we must frost
you must frost
they must frost 	I must be frosting
you must be frosting
he must be frosting
we must be frosting
you must be frosting
they must be frosting	I must have frosted
you must have frosted
he must have frosted
we must have frosted
you must have frosted
they must have frosted	I must have been frosting
you must have been frosting
he must have been frosting
we must have been frosting
you must have been frosting
they must have been frosting	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't frost
you mustn't frost
he mustn't frost
we mustn't frost
you mustn't frost
they mustn't frost 	I mustn't be frosting
you mustn't be frosting
he mustn't be frosting
we mustn't be frosting
you mustn't be frosting
they mustn't be frosting	I mustn't have frosted
you mustn't have frosted
he mustn't have frosted
we mustn't have frosted
you mustn't have frosted
they mustn't have frosted	I mustn't have been frosting
you mustn't have been frosting
he mustn't have been frosting
we mustn't have been frosting
you mustn't have been frosting
they mustn't have been frosting	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I frost?
must you frost?
must he frost?
must we frost?
must you frost?
must they frost? 	must I be frosting?
must you be frosting?
must he be frosting?
must we be frosting?
must you be frosting?
must they be frosting? 	must I have frosted?
must you have frosted?
must he have frosted?
must we have frosted?
must you have frosted?
must they have frosted? 	must I have been frosting?
must you have been frosting?
must he have been frosting?
must we have been frosting?
must you have been frosting?
must they have been frosting? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I frost?
mustn't you frost?
mustn't he frost?
mustn't we frost?
mustn't you frost?
mustn't they frost? 	mustn't I be frosting?
mustn't you be frosting?
mustn't he be frosting?
mustn't we be frosting?
mustn't you be frosting?
mustn't they be frosting? 	mustn't I have frosted?
mustn't you have frosted?
mustn't he have frosted?
mustn't we have frosted?
mustn't you have frosted?
mustn't they have frosted? 	mustn't I have been frosting?
mustn't you have been frosting?
mustn't he have been frosting?
mustn't we have been frosting?
mustn't you have been frosting?
mustn't they have been frosting?