I must counterweight you must counterweight he must counterweight we must counterweight you must counterweight they must counterweight
V-ing form
I must be counterweighting you must be counterweighting he must be counterweighting we must be counterweighting you must be counterweighting they must be counterweighting
Perfect
I must have counterweighted you must have counterweighted he must have counterweighted we must have counterweighted you must have counterweighted they must have counterweighted
V-ing perfect
I must have been counterweighting you must have been counterweighting he must have been counterweighting we must have been counterweighting you must have been counterweighting they must have been counterweighting
Negation
Simple form
I must not counterweight you must not counterweight he must not counterweight we must not counterweight you must not counterweight they must not counterweight
V-ing form
I must not be counterweighting you must not be counterweighting he must not be counterweighting we must not be counterweighting you must not be counterweighting they must not be counterweighting
Perfect
I must not have counterweighted you must not have counterweighted he must not have counterweighted we must not have counterweighted you must not have counterweighted they must not have counterweighted
V-ing perfect
I must not have been counterweighting you must not have been counterweighting he must not have been counterweighting we must not have been counterweighting you must not have been counterweighting they must not have been counterweighting
Interrogative form
Simple form
must I counterweight? must you counterweight? must he counterweight? must we counterweight? must you counterweight? must they counterweight?
V-ing form
must I be counterweighting? must you be counterweighting? must he be counterweighting? must we be counterweighting? must you be counterweighting? must they be counterweighting?
Perfect
must I have counterweighted? must you have counterweighted? must he have counterweighted? must we have counterweighted? must you have counterweighted? must they have counterweighted?
V-ing perfect
must I have been counterweighting? must you have been counterweighting? must he have been counterweighting? must we have been counterweighting? must you have been counterweighting? must they have been counterweighting?
Interro-negative form
Simple form
must I not counterweight? must you not counterweight? must he not counterweight? must we not counterweight? must you not counterweight? must they not counterweight?
V-ing form
must I not be counterweighting? must you not be counterweighting? must he not be counterweighting? must we not be counterweighting? must you not be counterweighting? must they not be counterweighting?
Perfect
must I not have counterweighted? must you not have counterweighted? must he not have counterweighted? must we not have counterweighted? must you not have counterweighted? must they not have counterweighted?
V-ing perfect
must I not have been counterweighting? must you not have been counterweighting? must he not have been counterweighting? must we not have been counterweighting? must you not have been counterweighting? must they not have been counterweighting?