I must dig you must dig he must dig we must dig you must dig they must dig
V-ing form
I must be digging you must be digging he must be digging we must be digging you must be digging they must be digging
Perfect
I must have dug you must have dug he must have dug we must have dug you must have dug they must have dug
V-ing perfect
I must have been digging you must have been digging he must have been digging we must have been digging you must have been digging they must have been digging
Negation
Simple form
I mustn't dig you mustn't dig he mustn't dig we mustn't dig you mustn't dig they mustn't dig
V-ing form
I mustn't be digging you mustn't be digging he mustn't be digging we mustn't be digging you mustn't be digging they mustn't be digging
Perfect
I mustn't have dug you mustn't have dug he mustn't have dug we mustn't have dug you mustn't have dug they mustn't have dug
V-ing perfect
I mustn't have been digging you mustn't have been digging he mustn't have been digging we mustn't have been digging you mustn't have been digging they mustn't have been digging
Interrogative form
Simple form
must I dig? must you dig? must he dig? must we dig? must you dig? must they dig?
V-ing form
must I be digging? must you be digging? must he be digging? must we be digging? must you be digging? must they be digging?
Perfect
must I have dug? must you have dug? must he have dug? must we have dug? must you have dug? must they have dug?
V-ing perfect
must I have been digging? must you have been digging? must he have been digging? must we have been digging? must you have been digging? must they have been digging?
Interro-negative form
Simple form
mustn't I dig? mustn't you dig? mustn't he dig? mustn't we dig? mustn't you dig? mustn't they dig?
V-ing form
mustn't I be digging? mustn't you be digging? mustn't he be digging? mustn't we be digging? mustn't you be digging? mustn't they be digging?
Perfect
mustn't I have dug? mustn't you have dug? mustn't he have dug? mustn't we have dug? mustn't you have dug? mustn't they have dug?
V-ing perfect
mustn't I have been digging? mustn't you have been digging? mustn't he have been digging? mustn't we have been digging? mustn't you have been digging? mustn't they have been digging?