must scab
Regular verb: scab - scabbed- scabbed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must scab
you must scab
she must scab
we must scab
you must scab
they must scab 	I must be scabbing
you must be scabbing
she must be scabbing
we must be scabbing
you must be scabbing
they must be scabbing	I must have scabbed
you must have scabbed
she must have scabbed
we must have scabbed
you must have scabbed
they must have scabbed	I must have been scabbing
you must have been scabbing
she must have been scabbing
we must have been scabbing
you must have been scabbing
they must have been scabbing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't scab
you mustn't scab
she mustn't scab
we mustn't scab
you mustn't scab
they mustn't scab 	I mustn't be scabbing
you mustn't be scabbing
she mustn't be scabbing
we mustn't be scabbing
you mustn't be scabbing
they mustn't be scabbing	I mustn't have scabbed
you mustn't have scabbed
she mustn't have scabbed
we mustn't have scabbed
you mustn't have scabbed
they mustn't have scabbed	I mustn't have been scabbing
you mustn't have been scabbing
she mustn't have been scabbing
we mustn't have been scabbing
you mustn't have been scabbing
they mustn't have been scabbing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I scab?
must you scab?
must she scab?
must we scab?
must you scab?
must they scab? 	must I be scabbing?
must you be scabbing?
must she be scabbing?
must we be scabbing?
must you be scabbing?
must they be scabbing? 	must I have scabbed?
must you have scabbed?
must she have scabbed?
must we have scabbed?
must you have scabbed?
must they have scabbed? 	must I have been scabbing?
must you have been scabbing?
must she have been scabbing?
must we have been scabbing?
must you have been scabbing?
must they have been scabbing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I scab?
mustn't you scab?
mustn't she scab?
mustn't we scab?
mustn't you scab?
mustn't they scab? 	mustn't I be scabbing?
mustn't you be scabbing?
mustn't she be scabbing?
mustn't we be scabbing?
mustn't you be scabbing?
mustn't they be scabbing? 	mustn't I have scabbed?
mustn't you have scabbed?
mustn't she have scabbed?
mustn't we have scabbed?
mustn't you have scabbed?
mustn't they have scabbed? 	mustn't I have been scabbing?
mustn't you have been scabbing?
mustn't she have been scabbing?
mustn't we have been scabbing?
mustn't you have been scabbing?
mustn't they have been scabbing?