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 must not double you must not double he must not double we must not double you must not double they must not double	I must not be doubling you must not be doubling he must not be doubling we must not be doubling you must not be doubling they must not be doubling
Perfect	V-ing perfect
I must not have doubled you must not have doubled he must not have doubled we must not have doubled you must not have doubled they must not have doubled	I must not have been doubling you must not have been doubling he must not have been doubling we must not have been doubling you must not have been doubling they must not 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
must I not double? must you not double? must he not double? must we not double? must you not double? must they not double?	must I not be doubling? must you not be doubling? must he not be doubling? must we not be doubling? must you not be doubling? must they not be doubling?
Perfect	V-ing perfect
must I not have doubled? must you not have doubled? must he not have doubled? must we not have doubled? must you not have doubled? must they not have doubled?	must I not have been doubling? must you not have been doubling? must he not have been doubling? must we not have been doubling? must you not have been doubling? must they not have been doubling?