must catalyse
Regular verb: catalyse - catalysed- catalysed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must catalyse
you must catalyse
she must catalyse
we must catalyse
you must catalyse
they must catalyse 	I must be catalysing
you must be catalysing
she must be catalysing
we must be catalysing
you must be catalysing
they must be catalysing	I must have catalysed
you must have catalysed
she must have catalysed
we must have catalysed
you must have catalysed
they must have catalysed	I must have been catalysing
you must have been catalysing
she must have been catalysing
we must have been catalysing
you must have been catalysing
they must have been catalysing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not catalyse
you must not catalyse
she must not catalyse
we must not catalyse
you must not catalyse
they must not catalyse 	I must not be catalysing
you must not be catalysing
she must not be catalysing
we must not be catalysing
you must not be catalysing
they must not be catalysing	I must not have catalysed
you must not have catalysed
she must not have catalysed
we must not have catalysed
you must not have catalysed
they must not have catalysed	I must not have been catalysing
you must not have been catalysing
she must not have been catalysing
we must not have been catalysing
you must not have been catalysing
they must not have been catalysing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I catalyse?
must you catalyse?
must she catalyse?
must we catalyse?
must you catalyse?
must they catalyse? 	must I be catalysing?
must you be catalysing?
must she be catalysing?
must we be catalysing?
must you be catalysing?
must they be catalysing? 	must I have catalysed?
must you have catalysed?
must she have catalysed?
must we have catalysed?
must you have catalysed?
must they have catalysed? 	must I have been catalysing?
must you have been catalysing?
must she have been catalysing?
must we have been catalysing?
must you have been catalysing?
must they have been catalysing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not catalyse?
must you not catalyse?
must she not catalyse?
must we not catalyse?
must you not catalyse?
must they not catalyse? 	must I not be catalysing?
must you not be catalysing?
must she not be catalysing?
must we not be catalysing?
must you not be catalysing?
must they not be catalysing? 	must I not have catalysed?
must you not have catalysed?
must she not have catalysed?
must we not have catalysed?
must you not have catalysed?
must they not have catalysed? 	must I not have been catalysing?
must you not have been catalysing?
must she not have been catalysing?
must we not have been catalysing?
must you not have been catalysing?
must they not have been catalysing?