must smooth
Regular verb: smooth - smoothed- smoothed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must smooth
you must smooth
she must smooth
we must smooth
you must smooth
they must smooth 	I must be smoothing
you must be smoothing
she must be smoothing
we must be smoothing
you must be smoothing
they must be smoothing	I must have smoothed
you must have smoothed
she 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
she must have been smoothing
we must have been smoothing
you must have been smoothing
they must have been smoothing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not smooth
you must not smooth
she 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
she 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
she 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
she must not have been smoothing
we must not have been smoothing
you must not have been smoothing
they must not have been smoothing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I smooth?
must you smooth?
must she smooth?
must we smooth?
must you smooth?
must they smooth? 	must I be smoothing?
must you be smoothing?
must she be smoothing?
must we be smoothing?
must you be smoothing?
must they be smoothing? 	must I have smoothed?
must you have smoothed?
must she 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 she have been smoothing?
must we have been smoothing?
must you have been smoothing?
must they have been smoothing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not smooth?
must you not smooth?
must she 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 she 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 she 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 she not have been smoothing?
must we not have been smoothing?
must you not have been smoothing?
must they not have been smoothing?