I must master you must master he must master we must master you must master they must master
Forma con V-ing
I must be mastering you must be mastering he must be mastering we must be mastering you must be mastering they must be mastering
Perfecto
I must have mastered you must have mastered he must have mastered we must have mastered you must have mastered they must have mastered
Perfecto con V-ing
I must have been mastering you must have been mastering he must have been mastering we must have been mastering you must have been mastering they must have been mastering
Negación
Forma simple
I must not master you must not master he must not master we must not master you must not master they must not master
Forma con V-ing
I must not be mastering you must not be mastering he must not be mastering we must not be mastering you must not be mastering they must not be mastering
Perfecto
I must not have mastered you must not have mastered he must not have mastered we must not have mastered you must not have mastered they must not have mastered
Perfecto con V-ing
I must not have been mastering you must not have been mastering he must not have been mastering we must not have been mastering you must not have been mastering they must not have been mastering
Forma interrogativa
Forma simple
must I master? must you master? must he master? must we master? must you master? must they master?
Forma con V-ing
must I be mastering? must you be mastering? must he be mastering? must we be mastering? must you be mastering? must they be mastering?
Perfecto
must I have mastered? must you have mastered? must he have mastered? must we have mastered? must you have mastered? must they have mastered?
Perfecto con V-ing
must I have been mastering? must you have been mastering? must he have been mastering? must we have been mastering? must you have been mastering? must they have been mastering?
Forma interro-negativa
Forma simple
must I not master? must you not master? must he not master? must we not master? must you not master? must they not master?
Forma con V-ing
must I not be mastering? must you not be mastering? must he not be mastering? must we not be mastering? must you not be mastering? must they not be mastering?
Perfecto
must I not have mastered? must you not have mastered? must he not have mastered? must we not have mastered? must you not have mastered? must they not have mastered?
Perfecto con V-ing
must I not have been mastering? must you not have been mastering? must he not have been mastering? must we not have been mastering? must you not have been mastering? must they not have been mastering?