I must tug you must tug he must tug we must tug you must tug they must tug
V-ing form
I must be tugging you must be tugging he must be tugging we must be tugging you must be tugging they must be tugging
Perfect
I must have tugged you must have tugged he must have tugged we must have tugged you must have tugged they must have tugged
V-ing perfect
I must have been tugging you must have been tugging he must have been tugging we must have been tugging you must have been tugging they must have been tugging
Negation
Simple form
I must not tug you must not tug he must not tug we must not tug you must not tug they must not tug
V-ing form
I must not be tugging you must not be tugging he must not be tugging we must not be tugging you must not be tugging they must not be tugging
Perfect
I must not have tugged you must not have tugged he must not have tugged we must not have tugged you must not have tugged they must not have tugged
V-ing perfect
I must not have been tugging you must not have been tugging he must not have been tugging we must not have been tugging you must not have been tugging they must not have been tugging
Interrogative form
Simple form
must I tug? must you tug? must he tug? must we tug? must you tug? must they tug?
V-ing form
must I be tugging? must you be tugging? must he be tugging? must we be tugging? must you be tugging? must they be tugging?
Perfect
must I have tugged? must you have tugged? must he have tugged? must we have tugged? must you have tugged? must they have tugged?
V-ing perfect
must I have been tugging? must you have been tugging? must he have been tugging? must we have been tugging? must you have been tugging? must they have been tugging?
Interro-negative form
Simple form
must I not tug? must you not tug? must he not tug? must we not tug? must you not tug? must they not tug?
V-ing form
must I not be tugging? must you not be tugging? must he not be tugging? must we not be tugging? must you not be tugging? must they not be tugging?
Perfect
must I not have tugged? must you not have tugged? must he not have tugged? must we not have tugged? must you not have tugged? must they not have tugged?
V-ing perfect
must I not have been tugging? must you not have been tugging? must he not have been tugging? must we not have been tugging? must you not have been tugging? must they not have been tugging?