must retreat
Regular verb: retreat - retreated- retreated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must retreat
you must retreat
he must retreat
we must retreat
you must retreat
they must retreat 	I must be retreating
you must be retreating
he must be retreating
we must be retreating
you must be retreating
they must be retreating	I must have retreated
you must have retreated
he must have retreated
we must have retreated
you must have retreated
they must have retreated	I must have been retreating
you must have been retreating
he must have been retreating
we must have been retreating
you must have been retreating
they must have been retreating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't retreat
you mustn't retreat
he mustn't retreat
we mustn't retreat
you mustn't retreat
they mustn't retreat 	I mustn't be retreating
you mustn't be retreating
he mustn't be retreating
we mustn't be retreating
you mustn't be retreating
they mustn't be retreating	I mustn't have retreated
you mustn't have retreated
he mustn't have retreated
we mustn't have retreated
you mustn't have retreated
they mustn't have retreated	I mustn't have been retreating
you mustn't have been retreating
he mustn't have been retreating
we mustn't have been retreating
you mustn't have been retreating
they mustn't have been retreating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I retreat?
must you retreat?
must he retreat?
must we retreat?
must you retreat?
must they retreat? 	must I be retreating?
must you be retreating?
must he be retreating?
must we be retreating?
must you be retreating?
must they be retreating? 	must I have retreated?
must you have retreated?
must he have retreated?
must we have retreated?
must you have retreated?
must they have retreated? 	must I have been retreating?
must you have been retreating?
must he have been retreating?
must we have been retreating?
must you have been retreating?
must they have been retreating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I retreat?
mustn't you retreat?
mustn't he retreat?
mustn't we retreat?
mustn't you retreat?
mustn't they retreat? 	mustn't I be retreating?
mustn't you be retreating?
mustn't he be retreating?
mustn't we be retreating?
mustn't you be retreating?
mustn't they be retreating? 	mustn't I have retreated?
mustn't you have retreated?
mustn't he have retreated?
mustn't we have retreated?
mustn't you have retreated?
mustn't they have retreated? 	mustn't I have been retreating?
mustn't you have been retreating?
mustn't he have been retreating?
mustn't we have been retreating?
mustn't you have been retreating?
mustn't they have been retreating?