English verb conjugation
MUST USE

Regular verb: use - used - used

Affirmation

Simple form	V-ing form
I must use you must use she must use we must use you must use they must use	I must be using you must be using she must be using we must be using you must be using they must be using
Perfect	V-ing perfect
I must have used you must have used she must have used we must have used you must have used they must have used	I must have been using you must have been using she must have been using we must have been using you must have been using they must have been using

Negation

Simple form	V-ing form
I mustn't use you mustn't use she mustn't use we mustn't use you mustn't use they mustn't use	I mustn't be using you mustn't be using she mustn't be using we mustn't be using you mustn't be using they mustn't be using
Perfect	V-ing perfect
I mustn't have used you mustn't have used she mustn't have used we mustn't have used you mustn't have used they mustn't have used	I mustn't have been using you mustn't have been using she mustn't have been using we mustn't have been using you mustn't have been using they mustn't have been using

Interrogative form

Simple form	V-ing form
must I use? must you use? must she use? must we use? must you use? must they use?	must I be using? must you be using? must she be using? must we be using? must you be using? must they be using?
Perfect	V-ing perfect
must I have used? must you have used? must she have used? must we have used? must you have used? must they have used?	must I have been using? must you have been using? must she have been using? must we have been using? must you have been using? must they have been using?

Interro-negative form

Simple form	V-ing form
mustn't I use? mustn't you use? mustn't she use? mustn't we use? mustn't you use? mustn't they use?	mustn't I be using? mustn't you be using? mustn't she be using? mustn't we be using? mustn't you be using? mustn't they be using?
Perfect	V-ing perfect
mustn't I have used? mustn't you have used? mustn't she have used? mustn't we have used? mustn't you have used? mustn't they have used?	mustn't I have been using? mustn't you have been using? mustn't she have been using? mustn't we have been using? mustn't you have been using? mustn't they have been using?