I must certify you must certify he must certify we must certify you must certify they must certify
Forma con V-ing
I must be certifying you must be certifying he must be certifying we must be certifying you must be certifying they must be certifying
Perfecto
I must have certified you must have certified he must have certified we must have certified you must have certified they must have certified
Perfecto con V-ing
I must have been certifying you must have been certifying he must have been certifying we must have been certifying you must have been certifying they must have been certifying
Negación
Forma simple
I mustn't certify you mustn't certify he mustn't certify we mustn't certify you mustn't certify they mustn't certify
Forma con V-ing
I mustn't be certifying you mustn't be certifying he mustn't be certifying we mustn't be certifying you mustn't be certifying they mustn't be certifying
Perfecto
I mustn't have certified you mustn't have certified he mustn't have certified we mustn't have certified you mustn't have certified they mustn't have certified
Perfecto con V-ing
I mustn't have been certifying you mustn't have been certifying he mustn't have been certifying we mustn't have been certifying you mustn't have been certifying they mustn't have been certifying
Forma interrogativa
Forma simple
must I certify? must you certify? must he certify? must we certify? must you certify? must they certify?
Forma con V-ing
must I be certifying? must you be certifying? must he be certifying? must we be certifying? must you be certifying? must they be certifying?
Perfecto
must I have certified? must you have certified? must he have certified? must we have certified? must you have certified? must they have certified?
Perfecto con V-ing
must I have been certifying? must you have been certifying? must he have been certifying? must we have been certifying? must you have been certifying? must they have been certifying?
Forma interro-negativa
Forma simple
mustn't I certify? mustn't you certify? mustn't he certify? mustn't we certify? mustn't you certify? mustn't they certify?
Forma con V-ing
mustn't I be certifying? mustn't you be certifying? mustn't he be certifying? mustn't we be certifying? mustn't you be certifying? mustn't they be certifying?
Perfecto
mustn't I have certified? mustn't you have certified? mustn't he have certified? mustn't we have certified? mustn't you have certified? mustn't they have certified?
Perfecto con V-ing
mustn't I have been certifying? mustn't you have been certifying? mustn't he have been certifying? mustn't we have been certifying? mustn't you have been certifying? mustn't they have been certifying?