must smooth
Verbo regular: smooth - smoothed- smoothed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must smooth
you must smooth
he must smooth
we must smooth
you must smooth
they must smooth 	I must be smoothing
you must be smoothing
he must be smoothing
we must be smoothing
you must be smoothing
they must be smoothing	I must have smoothed
you must have smoothed
he must have smoothed
we must have smoothed
you must have smoothed
they must have smoothed	I must have been smoothing
you must have been smoothing
he must have been smoothing
we must have been smoothing
you must have been smoothing
they must have been smoothing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not smooth
you must not smooth
he must not smooth
we must not smooth
you must not smooth
they must not smooth 	I must not be smoothing
you must not be smoothing
he must not be smoothing
we must not be smoothing
you must not be smoothing
they must not be smoothing	I must not have smoothed
you must not have smoothed
he must not have smoothed
we must not have smoothed
you must not have smoothed
they must not have smoothed	I must not have been smoothing
you must not have been smoothing
he must not have been smoothing
we must not have been smoothing
you must not have been smoothing
they must not have been smoothing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I smooth?
must you smooth?
must he smooth?
must we smooth?
must you smooth?
must they smooth? 	must I be smoothing?
must you be smoothing?
must he be smoothing?
must we be smoothing?
must you be smoothing?
must they be smoothing? 	must I have smoothed?
must you have smoothed?
must he have smoothed?
must we have smoothed?
must you have smoothed?
must they have smoothed? 	must I have been smoothing?
must you have been smoothing?
must he have been smoothing?
must we have been smoothing?
must you have been smoothing?
must they have been smoothing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not smooth?
must you not smooth?
must he not smooth?
must we not smooth?
must you not smooth?
must they not smooth? 	must I not be smoothing?
must you not be smoothing?
must he not be smoothing?
must we not be smoothing?
must you not be smoothing?
must they not be smoothing? 	must I not have smoothed?
must you not have smoothed?
must he not have smoothed?
must we not have smoothed?
must you not have smoothed?
must they not have smoothed? 	must I not have been smoothing?
must you not have been smoothing?
must he not have been smoothing?
must we not have been smoothing?
must you not have been smoothing?
must they not have been smoothing?