must tariff
Verbo regular: tariff - tariffed- tariffed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must tariff
you must tariff
he must tariff
we must tariff
you must tariff
they must tariff 	I must be tariffing
you must be tariffing
he must be tariffing
we must be tariffing
you must be tariffing
they must be tariffing	I must have tariffed
you must have tariffed
he must have tariffed
we must have tariffed
you must have tariffed
they must have tariffed	I must have been tariffing
you must have been tariffing
he must have been tariffing
we must have been tariffing
you must have been tariffing
they must have been tariffing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't tariff
you mustn't tariff
he mustn't tariff
we mustn't tariff
you mustn't tariff
they mustn't tariff 	I mustn't be tariffing
you mustn't be tariffing
he mustn't be tariffing
we mustn't be tariffing
you mustn't be tariffing
they mustn't be tariffing	I mustn't have tariffed
you mustn't have tariffed
he mustn't have tariffed
we mustn't have tariffed
you mustn't have tariffed
they mustn't have tariffed	I mustn't have been tariffing
you mustn't have been tariffing
he mustn't have been tariffing
we mustn't have been tariffing
you mustn't have been tariffing
they mustn't have been tariffing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I tariff?
must you tariff?
must he tariff?
must we tariff?
must you tariff?
must they tariff? 	must I be tariffing?
must you be tariffing?
must he be tariffing?
must we be tariffing?
must you be tariffing?
must they be tariffing? 	must I have tariffed?
must you have tariffed?
must he have tariffed?
must we have tariffed?
must you have tariffed?
must they have tariffed? 	must I have been tariffing?
must you have been tariffing?
must he have been tariffing?
must we have been tariffing?
must you have been tariffing?
must they have been tariffing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I tariff?
mustn't you tariff?
mustn't he tariff?
mustn't we tariff?
mustn't you tariff?
mustn't they tariff? 	mustn't I be tariffing?
mustn't you be tariffing?
mustn't he be tariffing?
mustn't we be tariffing?
mustn't you be tariffing?
mustn't they be tariffing? 	mustn't I have tariffed?
mustn't you have tariffed?
mustn't he have tariffed?
mustn't we have tariffed?
mustn't you have tariffed?
mustn't they have tariffed? 	mustn't I have been tariffing?
mustn't you have been tariffing?
mustn't he have been tariffing?
mustn't we have been tariffing?
mustn't you have been tariffing?
mustn't they have been tariffing?