must whistle
Verbo regular: whistle - whistled- whistled

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must whistle
you must whistle
he must whistle
we must whistle
you must whistle
they must whistle 	I must be whistling
you must be whistling
he must be whistling
we must be whistling
you must be whistling
they must be whistling	I must have whistled
you must have whistled
he must have whistled
we must have whistled
you must have whistled
they must have whistled	I must have been whistling
you must have been whistling
he must have been whistling
we must have been whistling
you must have been whistling
they must have been whistling	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not whistle
you must not whistle
he must not whistle
we must not whistle
you must not whistle
they must not whistle 	I must not be whistling
you must not be whistling
he must not be whistling
we must not be whistling
you must not be whistling
they must not be whistling	I must not have whistled
you must not have whistled
he must not have whistled
we must not have whistled
you must not have whistled
they must not have whistled	I must not have been whistling
you must not have been whistling
he must not have been whistling
we must not have been whistling
you must not have been whistling
they must not have been whistling	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I whistle?
must you whistle?
must he whistle?
must we whistle?
must you whistle?
must they whistle? 	must I be whistling?
must you be whistling?
must he be whistling?
must we be whistling?
must you be whistling?
must they be whistling? 	must I have whistled?
must you have whistled?
must he have whistled?
must we have whistled?
must you have whistled?
must they have whistled? 	must I have been whistling?
must you have been whistling?
must he have been whistling?
must we have been whistling?
must you have been whistling?
must they have been whistling? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not whistle?
must you not whistle?
must he not whistle?
must we not whistle?
must you not whistle?
must they not whistle? 	must I not be whistling?
must you not be whistling?
must he not be whistling?
must we not be whistling?
must you not be whistling?
must they not be whistling? 	must I not have whistled?
must you not have whistled?
must he not have whistled?
must we not have whistled?
must you not have whistled?
must they not have whistled? 	must I not have been whistling?
must you not have been whistling?
must he not have been whistling?
must we not have been whistling?
must you not have been whistling?
must they not have been whistling?