must skirr
Regular verb: skirr - skirred- skirred

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must skirr
you must skirr
he must skirr
we must skirr
you must skirr
they must skirr 	I must be skirring
you must be skirring
he must be skirring
we must be skirring
you must be skirring
they must be skirring	I must have skirred
you must have skirred
he must have skirred
we must have skirred
you must have skirred
they must have skirred	I must have been skirring
you must have been skirring
he must have been skirring
we must have been skirring
you must have been skirring
they must have been skirring	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't skirr
you mustn't skirr
he mustn't skirr
we mustn't skirr
you mustn't skirr
they mustn't skirr 	I mustn't be skirring
you mustn't be skirring
he mustn't be skirring
we mustn't be skirring
you mustn't be skirring
they mustn't be skirring	I mustn't have skirred
you mustn't have skirred
he mustn't have skirred
we mustn't have skirred
you mustn't have skirred
they mustn't have skirred	I mustn't have been skirring
you mustn't have been skirring
he mustn't have been skirring
we mustn't have been skirring
you mustn't have been skirring
they mustn't have been skirring	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I skirr?
must you skirr?
must he skirr?
must we skirr?
must you skirr?
must they skirr? 	must I be skirring?
must you be skirring?
must he be skirring?
must we be skirring?
must you be skirring?
must they be skirring? 	must I have skirred?
must you have skirred?
must he have skirred?
must we have skirred?
must you have skirred?
must they have skirred? 	must I have been skirring?
must you have been skirring?
must he have been skirring?
must we have been skirring?
must you have been skirring?
must they have been skirring? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I skirr?
mustn't you skirr?
mustn't he skirr?
mustn't we skirr?
mustn't you skirr?
mustn't they skirr? 	mustn't I be skirring?
mustn't you be skirring?
mustn't he be skirring?
mustn't we be skirring?
mustn't you be skirring?
mustn't they be skirring? 	mustn't I have skirred?
mustn't you have skirred?
mustn't he have skirred?
mustn't we have skirred?
mustn't you have skirred?
mustn't they have skirred? 	mustn't I have been skirring?
mustn't you have been skirring?
mustn't he have been skirring?
mustn't we have been skirring?
mustn't you have been skirring?
mustn't they have been skirring?