must counterweigh
Regular verb: counterweigh - counterweighed- counterweighed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must counterweigh
you must counterweigh
he must counterweigh
we must counterweigh
you must counterweigh
they must counterweigh 	I must be counterweighing
you must be counterweighing
he must be counterweighing
we must be counterweighing
you must be counterweighing
they must be counterweighing	I must have counterweighed
you must have counterweighed
he must have counterweighed
we must have counterweighed
you must have counterweighed
they must have counterweighed	I must have been counterweighing
you must have been counterweighing
he must have been counterweighing
we must have been counterweighing
you must have been counterweighing
they must have been counterweighing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not counterweigh
you must not counterweigh
he must not counterweigh
we must not counterweigh
you must not counterweigh
they must not counterweigh 	I must not be counterweighing
you must not be counterweighing
he must not be counterweighing
we must not be counterweighing
you must not be counterweighing
they must not be counterweighing	I must not have counterweighed
you must not have counterweighed
he must not have counterweighed
we must not have counterweighed
you must not have counterweighed
they must not have counterweighed	I must not have been counterweighing
you must not have been counterweighing
he must not have been counterweighing
we must not have been counterweighing
you must not have been counterweighing
they must not have been counterweighing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I counterweigh?
must you counterweigh?
must he counterweigh?
must we counterweigh?
must you counterweigh?
must they counterweigh? 	must I be counterweighing?
must you be counterweighing?
must he be counterweighing?
must we be counterweighing?
must you be counterweighing?
must they be counterweighing? 	must I have counterweighed?
must you have counterweighed?
must he have counterweighed?
must we have counterweighed?
must you have counterweighed?
must they have counterweighed? 	must I have been counterweighing?
must you have been counterweighing?
must he have been counterweighing?
must we have been counterweighing?
must you have been counterweighing?
must they have been counterweighing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not counterweigh?
must you not counterweigh?
must he not counterweigh?
must we not counterweigh?
must you not counterweigh?
must they not counterweigh? 	must I not be counterweighing?
must you not be counterweighing?
must he not be counterweighing?
must we not be counterweighing?
must you not be counterweighing?
must they not be counterweighing? 	must I not have counterweighed?
must you not have counterweighed?
must he not have counterweighed?
must we not have counterweighed?
must you not have counterweighed?
must they not have counterweighed? 	must I not have been counterweighing?
must you not have been counterweighing?
must he not have been counterweighing?
must we not have been counterweighing?
must you not have been counterweighing?
must they not have been counterweighing?