must crouch
Regular verb: crouch - crouched- crouched

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must crouch
you must crouch
she must crouch
we must crouch
you must crouch
they must crouch 	I must be crouching
you must be crouching
she must be crouching
we must be crouching
you must be crouching
they must be crouching	I must have crouched
you must have crouched
she must have crouched
we must have crouched
you must have crouched
they must have crouched	I must have been crouching
you must have been crouching
she must have been crouching
we must have been crouching
you must have been crouching
they must have been crouching	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not crouch
you must not crouch
she must not crouch
we must not crouch
you must not crouch
they must not crouch 	I must not be crouching
you must not be crouching
she must not be crouching
we must not be crouching
you must not be crouching
they must not be crouching	I must not have crouched
you must not have crouched
she must not have crouched
we must not have crouched
you must not have crouched
they must not have crouched	I must not have been crouching
you must not have been crouching
she must not have been crouching
we must not have been crouching
you must not have been crouching
they must not have been crouching	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I crouch?
must you crouch?
must she crouch?
must we crouch?
must you crouch?
must they crouch? 	must I be crouching?
must you be crouching?
must she be crouching?
must we be crouching?
must you be crouching?
must they be crouching? 	must I have crouched?
must you have crouched?
must she have crouched?
must we have crouched?
must you have crouched?
must they have crouched? 	must I have been crouching?
must you have been crouching?
must she have been crouching?
must we have been crouching?
must you have been crouching?
must they have been crouching? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not crouch?
must you not crouch?
must she not crouch?
must we not crouch?
must you not crouch?
must they not crouch? 	must I not be crouching?
must you not be crouching?
must she not be crouching?
must we not be crouching?
must you not be crouching?
must they not be crouching? 	must I not have crouched?
must you not have crouched?
must she not have crouched?
must we not have crouched?
must you not have crouched?
must they not have crouched? 	must I not have been crouching?
must you not have been crouching?
must she not have been crouching?
must we not have been crouching?
must you not have been crouching?
must they not have been crouching?