I must specialize you must specialize he must specialize we must specialize you must specialize they must specialize
V-ing form
I must be specializing you must be specializing he must be specializing we must be specializing you must be specializing they must be specializing
Perfect
I must have specialized you must have specialized he must have specialized we must have specialized you must have specialized they must have specialized
V-ing perfect
I must have been specializing you must have been specializing he must have been specializing we must have been specializing you must have been specializing they must have been specializing
Negation
Simple form
I must not specialize you must not specialize he must not specialize we must not specialize you must not specialize they must not specialize
V-ing form
I must not be specializing you must not be specializing he must not be specializing we must not be specializing you must not be specializing they must not be specializing
Perfect
I must not have specialized you must not have specialized he must not have specialized we must not have specialized you must not have specialized they must not have specialized
V-ing perfect
I must not have been specializing you must not have been specializing he must not have been specializing we must not have been specializing you must not have been specializing they must not have been specializing
Interrogative form
Simple form
must I specialize? must you specialize? must he specialize? must we specialize? must you specialize? must they specialize?
V-ing form
must I be specializing? must you be specializing? must he be specializing? must we be specializing? must you be specializing? must they be specializing?
Perfect
must I have specialized? must you have specialized? must he have specialized? must we have specialized? must you have specialized? must they have specialized?
V-ing perfect
must I have been specializing? must you have been specializing? must he have been specializing? must we have been specializing? must you have been specializing? must they have been specializing?
Interro-negative form
Simple form
must I not specialize? must you not specialize? must he not specialize? must we not specialize? must you not specialize? must they not specialize?
V-ing form
must I not be specializing? must you not be specializing? must he not be specializing? must we not be specializing? must you not be specializing? must they not be specializing?
Perfect
must I not have specialized? must you not have specialized? must he not have specialized? must we not have specialized? must you not have specialized? must they not have specialized?
V-ing perfect
must I not have been specializing? must you not have been specializing? must he not have been specializing? must we not have been specializing? must you not have been specializing? must they not have been specializing?