must alternate
Regular verb: alternate - alternated- alternated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must alternate
you must alternate
she must alternate
we must alternate
you must alternate
they must alternate 	I must be alternating
you must be alternating
she must be alternating
we must be alternating
you must be alternating
they must be alternating	I must have alternated
you must have alternated
she must have alternated
we must have alternated
you must have alternated
they must have alternated	I must have been alternating
you must have been alternating
she must have been alternating
we must have been alternating
you must have been alternating
they must have been alternating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't alternate
you mustn't alternate
she mustn't alternate
we mustn't alternate
you mustn't alternate
they mustn't alternate 	I mustn't be alternating
you mustn't be alternating
she mustn't be alternating
we mustn't be alternating
you mustn't be alternating
they mustn't be alternating	I mustn't have alternated
you mustn't have alternated
she mustn't have alternated
we mustn't have alternated
you mustn't have alternated
they mustn't have alternated	I mustn't have been alternating
you mustn't have been alternating
she mustn't have been alternating
we mustn't have been alternating
you mustn't have been alternating
they mustn't have been alternating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I alternate?
must you alternate?
must she alternate?
must we alternate?
must you alternate?
must they alternate? 	must I be alternating?
must you be alternating?
must she be alternating?
must we be alternating?
must you be alternating?
must they be alternating? 	must I have alternated?
must you have alternated?
must she have alternated?
must we have alternated?
must you have alternated?
must they have alternated? 	must I have been alternating?
must you have been alternating?
must she have been alternating?
must we have been alternating?
must you have been alternating?
must they have been alternating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I alternate?
mustn't you alternate?
mustn't she alternate?
mustn't we alternate?
mustn't you alternate?
mustn't they alternate? 	mustn't I be alternating?
mustn't you be alternating?
mustn't she be alternating?
mustn't we be alternating?
mustn't you be alternating?
mustn't they be alternating? 	mustn't I have alternated?
mustn't you have alternated?
mustn't she have alternated?
mustn't we have alternated?
mustn't you have alternated?
mustn't they have alternated? 	mustn't I have been alternating?
mustn't you have been alternating?
mustn't she have been alternating?
mustn't we have been alternating?
mustn't you have been alternating?
mustn't they have been alternating?