English verb conjugation
MUST DOUBLE

Regular verb: double - doubled - doubled

Affirmation

Simple form	V-ing form
I must double you must double he must double we must double you must double they must double	I must be doubling you must be doubling he must be doubling we must be doubling you must be doubling they must be doubling
Perfect	V-ing perfect
I must have doubled you must have doubled he must have doubled we must have doubled you must have doubled they must have doubled	I must have been doubling you must have been doubling he must have been doubling we must have been doubling you must have been doubling they must have been doubling

Negation

Simple form	V-ing form
I mustn't double you mustn't double he mustn't double we mustn't double you mustn't double they mustn't double	I mustn't be doubling you mustn't be doubling he mustn't be doubling we mustn't be doubling you mustn't be doubling they mustn't be doubling
Perfect	V-ing perfect
I mustn't have doubled you mustn't have doubled he mustn't have doubled we mustn't have doubled you mustn't have doubled they mustn't have doubled	I mustn't have been doubling you mustn't have been doubling he mustn't have been doubling we mustn't have been doubling you mustn't have been doubling they mustn't have been doubling

Interrogative form

Simple form	V-ing form
must I double? must you double? must he double? must we double? must you double? must they double?	must I be doubling? must you be doubling? must he be doubling? must we be doubling? must you be doubling? must they be doubling?
Perfect	V-ing perfect
must I have doubled? must you have doubled? must he have doubled? must we have doubled? must you have doubled? must they have doubled?	must I have been doubling? must you have been doubling? must he have been doubling? must we have been doubling? must you have been doubling? must they have been doubling?

Interro-negative form

Simple form	V-ing form
mustn't I double? mustn't you double? mustn't he double? mustn't we double? mustn't you double? mustn't they double?	mustn't I be doubling? mustn't you be doubling? mustn't he be doubling? mustn't we be doubling? mustn't you be doubling? mustn't they be doubling?
Perfect	V-ing perfect
mustn't I have doubled? mustn't you have doubled? mustn't he have doubled? mustn't we have doubled? mustn't you have doubled? mustn't they have doubled?	mustn't I have been doubling? mustn't you have been doubling? mustn't he have been doubling? mustn't we have been doubling? mustn't you have been doubling? mustn't they have been doubling?