must scum
Regular verb: scum - scummed- scummed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must scum
you must scum
he must scum
we must scum
you must scum
they must scum 	I must be scumming
you must be scumming
he must be scumming
we must be scumming
you must be scumming
they must be scumming	I must have scummed
you must have scummed
he must have scummed
we must have scummed
you must have scummed
they must have scummed	I must have been scumming
you must have been scumming
he must have been scumming
we must have been scumming
you must have been scumming
they must have been scumming	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not scum
you must not scum
he must not scum
we must not scum
you must not scum
they must not scum 	I must not be scumming
you must not be scumming
he must not be scumming
we must not be scumming
you must not be scumming
they must not be scumming	I must not have scummed
you must not have scummed
he must not have scummed
we must not have scummed
you must not have scummed
they must not have scummed	I must not have been scumming
you must not have been scumming
he must not have been scumming
we must not have been scumming
you must not have been scumming
they must not have been scumming	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I scum?
must you scum?
must he scum?
must we scum?
must you scum?
must they scum? 	must I be scumming?
must you be scumming?
must he be scumming?
must we be scumming?
must you be scumming?
must they be scumming? 	must I have scummed?
must you have scummed?
must he have scummed?
must we have scummed?
must you have scummed?
must they have scummed? 	must I have been scumming?
must you have been scumming?
must he have been scumming?
must we have been scumming?
must you have been scumming?
must they have been scumming? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not scum?
must you not scum?
must he not scum?
must we not scum?
must you not scum?
must they not scum? 	must I not be scumming?
must you not be scumming?
must he not be scumming?
must we not be scumming?
must you not be scumming?
must they not be scumming? 	must I not have scummed?
must you not have scummed?
must he not have scummed?
must we not have scummed?
must you not have scummed?
must they not have scummed? 	must I not have been scumming?
must you not have been scumming?
must he not have been scumming?
must we not have been scumming?
must you not have been scumming?
must they not have been scumming?