must constrain
Regular verb: constrain - constrained- constrained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must constrain
you must constrain
he must constrain
we must constrain
you must constrain
they must constrain 	I must be constraining
you must be constraining
he must be constraining
we must be constraining
you must be constraining
they must be constraining	I must have constrained
you must have constrained
he must have constrained
we must have constrained
you must have constrained
they must have constrained	I must have been constraining
you must have been constraining
he must have been constraining
we must have been constraining
you must have been constraining
they must have been constraining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't constrain
you mustn't constrain
he mustn't constrain
we mustn't constrain
you mustn't constrain
they mustn't constrain 	I mustn't be constraining
you mustn't be constraining
he mustn't be constraining
we mustn't be constraining
you mustn't be constraining
they mustn't be constraining	I mustn't have constrained
you mustn't have constrained
he mustn't have constrained
we mustn't have constrained
you mustn't have constrained
they mustn't have constrained	I mustn't have been constraining
you mustn't have been constraining
he mustn't have been constraining
we mustn't have been constraining
you mustn't have been constraining
they mustn't have been constraining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I constrain?
must you constrain?
must he constrain?
must we constrain?
must you constrain?
must they constrain? 	must I be constraining?
must you be constraining?
must he be constraining?
must we be constraining?
must you be constraining?
must they be constraining? 	must I have constrained?
must you have constrained?
must he have constrained?
must we have constrained?
must you have constrained?
must they have constrained? 	must I have been constraining?
must you have been constraining?
must he have been constraining?
must we have been constraining?
must you have been constraining?
must they have been constraining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I constrain?
mustn't you constrain?
mustn't he constrain?
mustn't we constrain?
mustn't you constrain?
mustn't they constrain? 	mustn't I be constraining?
mustn't you be constraining?
mustn't he be constraining?
mustn't we be constraining?
mustn't you be constraining?
mustn't they be constraining? 	mustn't I have constrained?
mustn't you have constrained?
mustn't he have constrained?
mustn't we have constrained?
mustn't you have constrained?
mustn't they have constrained? 	mustn't I have been constraining?
mustn't you have been constraining?
mustn't he have been constraining?
mustn't we have been constraining?
mustn't you have been constraining?
mustn't they have been constraining?