must counterweight
Regular verb: counterweight - counterweighted- counterweighted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must counterweight
you must counterweight
she must counterweight
we must counterweight
you must counterweight
they must counterweight 	I must be counterweighting
you must be counterweighting
she must be counterweighting
we must be counterweighting
you must be counterweighting
they must be counterweighting	I must have counterweighted
you must have counterweighted
she must have counterweighted
we must have counterweighted
you must have counterweighted
they must have counterweighted	I must have been counterweighting
you must have been counterweighting
she must have been counterweighting
we must have been counterweighting
you must have been counterweighting
they must have been counterweighting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't counterweight
you mustn't counterweight
she mustn't counterweight
we mustn't counterweight
you mustn't counterweight
they mustn't counterweight 	I mustn't be counterweighting
you mustn't be counterweighting
she mustn't be counterweighting
we mustn't be counterweighting
you mustn't be counterweighting
they mustn't be counterweighting	I mustn't have counterweighted
you mustn't have counterweighted
she mustn't have counterweighted
we mustn't have counterweighted
you mustn't have counterweighted
they mustn't have counterweighted	I mustn't have been counterweighting
you mustn't have been counterweighting
she mustn't have been counterweighting
we mustn't have been counterweighting
you mustn't have been counterweighting
they mustn't have been counterweighting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I counterweight?
must you counterweight?
must she counterweight?
must we counterweight?
must you counterweight?
must they counterweight? 	must I be counterweighting?
must you be counterweighting?
must she be counterweighting?
must we be counterweighting?
must you be counterweighting?
must they be counterweighting? 	must I have counterweighted?
must you have counterweighted?
must she have counterweighted?
must we have counterweighted?
must you have counterweighted?
must they have counterweighted? 	must I have been counterweighting?
must you have been counterweighting?
must she have been counterweighting?
must we have been counterweighting?
must you have been counterweighting?
must they have been counterweighting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I counterweight?
mustn't you counterweight?
mustn't she counterweight?
mustn't we counterweight?
mustn't you counterweight?
mustn't they counterweight? 	mustn't I be counterweighting?
mustn't you be counterweighting?
mustn't she be counterweighting?
mustn't we be counterweighting?
mustn't you be counterweighting?
mustn't they be counterweighting? 	mustn't I have counterweighted?
mustn't you have counterweighted?
mustn't she have counterweighted?
mustn't we have counterweighted?
mustn't you have counterweighted?
mustn't they have counterweighted? 	mustn't I have been counterweighting?
mustn't you have been counterweighting?
mustn't she have been counterweighting?
mustn't we have been counterweighting?
mustn't you have been counterweighting?
mustn't they have been counterweighting?