English verb conjugation
MUST RETRIEVE

Regular verb: retrieve - retrieved - retrieved

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
I mustn't retrieve you mustn't retrieve she mustn't retrieve we mustn't retrieve you mustn't retrieve they mustn't retrieve	I mustn't be retrieving you mustn't be retrieving she mustn't be retrieving we mustn't be retrieving you mustn't be retrieving they mustn't be retrieving
Perfect	V-ing perfect
I mustn't have retrieved you mustn't have retrieved she mustn't have retrieved we mustn't have retrieved you mustn't have retrieved they mustn't have retrieved	I mustn't have been retrieving you mustn't have been retrieving she mustn't have been retrieving we mustn't have been retrieving you mustn't have been retrieving they mustn't have been retrieving

Interrogative form

Simple form	V-ing form
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?
Perfect	V-ing perfect
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
mustn't I retrieve? mustn't you retrieve? mustn't she retrieve? mustn't we retrieve? mustn't you retrieve? mustn't they retrieve?	mustn't I be retrieving? mustn't you be retrieving? mustn't she be retrieving? mustn't we be retrieving? mustn't you be retrieving? mustn't they be retrieving?
Perfect	V-ing perfect
mustn't I have retrieved? mustn't you have retrieved? mustn't she have retrieved? mustn't we have retrieved? mustn't you have retrieved? mustn't they have retrieved?	mustn't I have been retrieving? mustn't you have been retrieving? mustn't she have been retrieving? mustn't we have been retrieving? mustn't you have been retrieving? mustn't they have been retrieving?