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 mustn't tug you mustn't tug he mustn't tug we mustn't tug you mustn't tug they mustn't tug
V-ing form
I mustn't be tugging you mustn't be tugging he mustn't be tugging we mustn't be tugging you mustn't be tugging they mustn't be tugging
Perfect
I mustn't have tugged you mustn't have tugged he mustn't have tugged we mustn't have tugged you mustn't have tugged they mustn't have tugged
V-ing perfect
I mustn't have been tugging you mustn't have been tugging he mustn't have been tugging we mustn't have been tugging you mustn't have been tugging they mustn't 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
mustn't I tug? mustn't you tug? mustn't he tug? mustn't we tug? mustn't you tug? mustn't they tug?
V-ing form
mustn't I be tugging? mustn't you be tugging? mustn't he be tugging? mustn't we be tugging? mustn't you be tugging? mustn't they be tugging?
Perfect
mustn't I have tugged? mustn't you have tugged? mustn't he have tugged? mustn't we have tugged? mustn't you have tugged? mustn't they have tugged?
V-ing perfect
mustn't I have been tugging? mustn't you have been tugging? mustn't he have been tugging? mustn't we have been tugging? mustn't you have been tugging? mustn't they have been tugging?