must vary
Verbo regular: vary - varied- varied

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must vary
you must vary
he must vary
we must vary
you must vary
they must vary 	I must be varying
you must be varying
he must be varying
we must be varying
you must be varying
they must be varying	I must have varied
you must have varied
he must have varied
we must have varied
you must have varied
they must have varied	I must have been varying
you must have been varying
he must have been varying
we must have been varying
you must have been varying
they must have been varying	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not vary
you must not vary
he must not vary
we must not vary
you must not vary
they must not vary 	I must not be varying
you must not be varying
he must not be varying
we must not be varying
you must not be varying
they must not be varying	I must not have varied
you must not have varied
he must not have varied
we must not have varied
you must not have varied
they must not have varied	I must not have been varying
you must not have been varying
he must not have been varying
we must not have been varying
you must not have been varying
they must not have been varying	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I vary?
must you vary?
must he vary?
must we vary?
must you vary?
must they vary? 	must I be varying?
must you be varying?
must he be varying?
must we be varying?
must you be varying?
must they be varying? 	must I have varied?
must you have varied?
must he have varied?
must we have varied?
must you have varied?
must they have varied? 	must I have been varying?
must you have been varying?
must he have been varying?
must we have been varying?
must you have been varying?
must they have been varying? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not vary?
must you not vary?
must he not vary?
must we not vary?
must you not vary?
must they not vary? 	must I not be varying?
must you not be varying?
must he not be varying?
must we not be varying?
must you not be varying?
must they not be varying? 	must I not have varied?
must you not have varied?
must he not have varied?
must we not have varied?
must you not have varied?
must they not have varied? 	must I not have been varying?
must you not have been varying?
must he not have been varying?
must we not have been varying?
must you not have been varying?
must they not have been varying?