English verb conjugation
MUST REFRAIN

Regular verb: refrain - refrained - refrained

Affirmation

Simple form	V-ing form
I must refrain you must refrain he must refrain we must refrain you must refrain they must refrain	I must be refraining you must be refraining he must be refraining we must be refraining you must be refraining they must be refraining
Perfect	V-ing perfect
I must have refrained you must have refrained he must have refrained we must have refrained you must have refrained they must have refrained	I must have been refraining you must have been refraining he must have been refraining we must have been refraining you must have been refraining they must have been refraining

Negation

Simple form	V-ing form
I must not refrain you must not refrain he must not refrain we must not refrain you must not refrain they must not refrain	I must not be refraining you must not be refraining he must not be refraining we must not be refraining you must not be refraining they must not be refraining
Perfect	V-ing perfect
I must not have refrained you must not have refrained he must not have refrained we must not have refrained you must not have refrained they must not have refrained	I must not have been refraining you must not have been refraining he must not have been refraining we must not have been refraining you must not have been refraining they must not have been refraining

Interrogative form

Simple form	V-ing form
must I refrain? must you refrain? must he refrain? must we refrain? must you refrain? must they refrain?	must I be refraining? must you be refraining? must he be refraining? must we be refraining? must you be refraining? must they be refraining?
Perfect	V-ing perfect
must I have refrained? must you have refrained? must he have refrained? must we have refrained? must you have refrained? must they have refrained?	must I have been refraining? must you have been refraining? must he have been refraining? must we have been refraining? must you have been refraining? must they have been refraining?

Interro-negative form

Simple form	V-ing form
must I not refrain? must you not refrain? must he not refrain? must we not refrain? must you not refrain? must they not refrain?	must I not be refraining? must you not be refraining? must he not be refraining? must we not be refraining? must you not be refraining? must they not be refraining?
Perfect	V-ing perfect
must I not have refrained? must you not have refrained? must he not have refrained? must we not have refrained? must you not have refrained? must they not have refrained?	must I not have been refraining? must you not have been refraining? must he not have been refraining? must we not have been refraining? must you not have been refraining? must they not have been refraining?