must discolour
Verbo regular: discolour - discoloured- discoloured

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must discolour
you must discolour
he must discolour
we must discolour
you must discolour
they must discolour 	I must be discolouring
you must be discolouring
he must be discolouring
we must be discolouring
you must be discolouring
they must be discolouring	I must have discoloured
you must have discoloured
he must have discoloured
we must have discoloured
you must have discoloured
they must have discoloured	I must have been discolouring
you must have been discolouring
he must have been discolouring
we must have been discolouring
you must have been discolouring
they must have been discolouring	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not discolour
you must not discolour
he must not discolour
we must not discolour
you must not discolour
they must not discolour 	I must not be discolouring
you must not be discolouring
he must not be discolouring
we must not be discolouring
you must not be discolouring
they must not be discolouring	I must not have discoloured
you must not have discoloured
he must not have discoloured
we must not have discoloured
you must not have discoloured
they must not have discoloured	I must not have been discolouring
you must not have been discolouring
he must not have been discolouring
we must not have been discolouring
you must not have been discolouring
they must not have been discolouring	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I discolour?
must you discolour?
must he discolour?
must we discolour?
must you discolour?
must they discolour? 	must I be discolouring?
must you be discolouring?
must he be discolouring?
must we be discolouring?
must you be discolouring?
must they be discolouring? 	must I have discoloured?
must you have discoloured?
must he have discoloured?
must we have discoloured?
must you have discoloured?
must they have discoloured? 	must I have been discolouring?
must you have been discolouring?
must he have been discolouring?
must we have been discolouring?
must you have been discolouring?
must they have been discolouring? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not discolour?
must you not discolour?
must he not discolour?
must we not discolour?
must you not discolour?
must they not discolour? 	must I not be discolouring?
must you not be discolouring?
must he not be discolouring?
must we not be discolouring?
must you not be discolouring?
must they not be discolouring? 	must I not have discoloured?
must you not have discoloured?
must he not have discoloured?
must we not have discoloured?
must you not have discoloured?
must they not have discoloured? 	must I not have been discolouring?
must you not have been discolouring?
must he not have been discolouring?
must we not have been discolouring?
must you not have been discolouring?
must they not have been discolouring?