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 must not alternate
you must not alternate
she must not alternate
we must not alternate
you must not alternate
they must not alternate 	I must not be alternating
you must not be alternating
she must not be alternating
we must not be alternating
you must not be alternating
they must not be alternating	I must not have alternated
you must not have alternated
she must not have alternated
we must not have alternated
you must not have alternated
they must not have alternated	I must not have been alternating
you must not have been alternating
she must not have been alternating
we must not have been alternating
you must not have been alternating
they must not 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 	
must I not alternate?
must you not alternate?
must she not alternate?
must we not alternate?
must you not alternate?
must they not alternate? 	must I not be alternating?
must you not be alternating?
must she not be alternating?
must we not be alternating?
must you not be alternating?
must they not be alternating? 	must I not have alternated?
must you not have alternated?
must she not have alternated?
must we not have alternated?
must you not have alternated?
must they not have alternated? 	must I not have been alternating?
must you not have been alternating?
must she not have been alternating?
must we not have been alternating?
must you not have been alternating?
must they not have been alternating?