must sigh
Regular verb: sigh - sighed- sighed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must sigh
you must sigh
she must sigh
we must sigh
you must sigh
they must sigh 	I must be sighing
you must be sighing
she must be sighing
we must be sighing
you must be sighing
they must be sighing	I must have sighed
you must have sighed
she must have sighed
we must have sighed
you must have sighed
they must have sighed	I must have been sighing
you must have been sighing
she must have been sighing
we must have been sighing
you must have been sighing
they must have been sighing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not sigh
you must not sigh
she must not sigh
we must not sigh
you must not sigh
they must not sigh 	I must not be sighing
you must not be sighing
she must not be sighing
we must not be sighing
you must not be sighing
they must not be sighing	I must not have sighed
you must not have sighed
she must not have sighed
we must not have sighed
you must not have sighed
they must not have sighed	I must not have been sighing
you must not have been sighing
she must not have been sighing
we must not have been sighing
you must not have been sighing
they must not have been sighing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I sigh?
must you sigh?
must she sigh?
must we sigh?
must you sigh?
must they sigh? 	must I be sighing?
must you be sighing?
must she be sighing?
must we be sighing?
must you be sighing?
must they be sighing? 	must I have sighed?
must you have sighed?
must she have sighed?
must we have sighed?
must you have sighed?
must they have sighed? 	must I have been sighing?
must you have been sighing?
must she have been sighing?
must we have been sighing?
must you have been sighing?
must they have been sighing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not sigh?
must you not sigh?
must she not sigh?
must we not sigh?
must you not sigh?
must they not sigh? 	must I not be sighing?
must you not be sighing?
must she not be sighing?
must we not be sighing?
must you not be sighing?
must they not be sighing? 	must I not have sighed?
must you not have sighed?
must she not have sighed?
must we not have sighed?
must you not have sighed?
must they not have sighed? 	must I not have been sighing?
must you not have been sighing?
must she not have been sighing?
must we not have been sighing?
must you not have been sighing?
must they not have been sighing?