must retrieve
Regular verb: retrieve - retrieved- retrieved

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must retrieve
you must retrieve
she must retrieve
we must retrieve
you must retrieve
they must retrieve 	I must be retrieving
you must be retrieving
she must be retrieving
we must be retrieving
you must be retrieving
they must be retrieving	I must have retrieved
you must have retrieved
she must have retrieved
we must have retrieved
you must have retrieved
they must have retrieved	I must have been retrieving
you must have been retrieving
she must have been retrieving
we must have been retrieving
you must have been retrieving
they must have been retrieving	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not retrieve
you must not retrieve
she must not retrieve
we must not retrieve
you must not retrieve
they must not retrieve 	I must not be retrieving
you must not be retrieving
she must not be retrieving
we must not be retrieving
you must not be retrieving
they must not be retrieving	I must not have retrieved
you must not have retrieved
she must not have retrieved
we must not have retrieved
you must not have retrieved
they must not have retrieved	I must not have been retrieving
you must not have been retrieving
she must not have been retrieving
we must not have been retrieving
you must not have been retrieving
they must not have been retrieving	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I retrieve?
must you retrieve?
must she retrieve?
must we retrieve?
must you retrieve?
must they retrieve? 	must I be retrieving?
must you be retrieving?
must she be retrieving?
must we be retrieving?
must you be retrieving?
must they be retrieving? 	must I have retrieved?
must you have retrieved?
must she have retrieved?
must we have retrieved?
must you have retrieved?
must they have retrieved? 	must I have been retrieving?
must you have been retrieving?
must she have been retrieving?
must we have been retrieving?
must you have been retrieving?
must they have been retrieving? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not retrieve?
must you not retrieve?
must she not retrieve?
must we not retrieve?
must you not retrieve?
must they not retrieve? 	must I not be retrieving?
must you not be retrieving?
must she not be retrieving?
must we not be retrieving?
must you not be retrieving?
must they not be retrieving? 	must I not have retrieved?
must you not have retrieved?
must she not have retrieved?
must we not have retrieved?
must you not have retrieved?
must they not have retrieved? 	must I not have been retrieving?
must you not have been retrieving?
must she not have been retrieving?
must we not have been retrieving?
must you not have been retrieving?
must they not have been retrieving?