must alternate
Regular verb: alternate - alternated- alternated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must alternate
you must alternate
he must alternate
we must alternate
you must alternate
they must alternate 	I must be alternating
you must be alternating
he must be alternating
we must be alternating
you must be alternating
they must be alternating	I must have alternated
you must have alternated
he 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
he 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
he 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
he 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
he 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
he 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 he alternate?
must we alternate?
must you alternate?
must they alternate? 	must I be alternating?
must you be alternating?
must he be alternating?
must we be alternating?
must you be alternating?
must they be alternating? 	must I have alternated?
must you have alternated?
must he 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 he 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 he 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 he 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 he 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 he not have been alternating?
must we not have been alternating?
must you not have been alternating?
must they not have been alternating?