must co-star
Regular verb: co-star - co-stared- co-stared

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must co-star
you must co-star
he must co-star
we must co-star
you must co-star
they must co-star 	I must be co-staring
you must be co-staring
he must be co-staring
we must be co-staring
you must be co-staring
they must be co-staring	I must have co-stared
you must have co-stared
he must have co-stared
we must have co-stared
you must have co-stared
they must have co-stared	I must have been co-staring
you must have been co-staring
he must have been co-staring
we must have been co-staring
you must have been co-staring
they must have been co-staring	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not co-star
you must not co-star
he must not co-star
we must not co-star
you must not co-star
they must not co-star 	I must not be co-staring
you must not be co-staring
he must not be co-staring
we must not be co-staring
you must not be co-staring
they must not be co-staring	I must not have co-stared
you must not have co-stared
he must not have co-stared
we must not have co-stared
you must not have co-stared
they must not have co-stared	I must not have been co-staring
you must not have been co-staring
he must not have been co-staring
we must not have been co-staring
you must not have been co-staring
they must not have been co-staring	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I co-star?
must you co-star?
must he co-star?
must we co-star?
must you co-star?
must they co-star? 	must I be co-staring?
must you be co-staring?
must he be co-staring?
must we be co-staring?
must you be co-staring?
must they be co-staring? 	must I have co-stared?
must you have co-stared?
must he have co-stared?
must we have co-stared?
must you have co-stared?
must they have co-stared? 	must I have been co-staring?
must you have been co-staring?
must he have been co-staring?
must we have been co-staring?
must you have been co-staring?
must they have been co-staring? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not co-star?
must you not co-star?
must he not co-star?
must we not co-star?
must you not co-star?
must they not co-star? 	must I not be co-staring?
must you not be co-staring?
must he not be co-staring?
must we not be co-staring?
must you not be co-staring?
must they not be co-staring? 	must I not have co-stared?
must you not have co-stared?
must he not have co-stared?
must we not have co-stared?
must you not have co-stared?
must they not have co-stared? 	must I not have been co-staring?
must you not have been co-staring?
must he not have been co-staring?
must we not have been co-staring?
must you not have been co-staring?
must they not have been co-staring?