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 must not dig you must not dig he must not dig we must not dig you must not dig they must not dig
V-ing form
I must not be digging you must not be digging he must not be digging we must not be digging you must not be digging they must not be digging
Perfect
I must not have dug you must not have dug he must not have dug we must not have dug you must not have dug they must not have dug
V-ing perfect
I must not have been digging you must not have been digging he must not have been digging we must not have been digging you must not have been digging they must not 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
must I not dig? must you not dig? must he not dig? must we not dig? must you not dig? must they not dig?
V-ing form
must I not be digging? must you not be digging? must he not be digging? must we not be digging? must you not be digging? must they not be digging?
Perfect
must I not have dug? must you not have dug? must he not have dug? must we not have dug? must you not have dug? must they not have dug?
V-ing perfect
must I not have been digging? must you not have been digging? must he not have been digging? must we not have been digging? must you not have been digging? must they not have been digging?