don't I certify? don't you certify? doesn't he certify? don't we certify? don't you certify? don't they certify?
Presente continuo
am I not certifying? aren't you certifying? isn't he certifying? aren't we certifying? aren't you certifying? aren't they certifying?
Pretérito
didn't I certify? didn't you certify? didn't he certify? didn't we certify? didn't you certify? didn't they certify?
Pretérito continuo
wasn't I certifying? weren't you certifying? wasn't he certifying? weren't we certifying? weren't you certifying? weren't they certifying?
Presente perfecto
haven't I certified? haven't you certified? hasn't he certified? haven't we certified? haven't you certified? haven't they certified?
Presente perfecto continuo
haven't I been certifying? haven't you been certifying? hasn't he been certifying? haven't we been certifying? haven't you been certifying? haven't they been certifying?
Pluscuamperfecto
hadn't I certified? hadn't you certified? hadn't he certified? hadn't we certified? hadn't you certified? hadn't they certified?
Pluscuamperfecto continuo
hadn't I been certifying? hadn't you been certifying? hadn't he been certifying? hadn't we been certifying? hadn't you been certifying? hadn't they been certifying?
Futuro simple
won't I certify? won't you certify? won't he certify? won't we certify? won't you certify? won't they certify?
Futuro continuo
won't I be certifying? won't you be certifying? won't he be certifying? won't we be certifying? won't you be certifying? won't they be certifying?
Futuro perfecto
won't I have certified? won't you have certified? won't he have certified? won't we have certified? won't you have certified? won't they have certified?
Futuro perfecto contínuo
won't I have been certifying? won't you have been certifying? won't he have been certifying? won't we have been certifying? won't you have been certifying? won't they have been certifying?
Condicional
Presente
wouldn't I certify? wouldn't you certify? wouldn't he certify? wouldn't we certify? wouldn't you certify? wouldn't they certify?
Presente continuo
wouldn't I be certifying? wouldn't you be certifying? wouldn't he be certifying? wouldn't we be certifying? wouldn't you be certifying? wouldn't they be certifying?
Passado
wouldn't I have certified? wouldn't you have certified? wouldn't he have certified? wouldn't we have certified? wouldn't you have certified? wouldn't they have certified?
Passado continuo
wouldn't I have been certifying? wouldn't you have been certifying? wouldn't he have been certifying? wouldn't we have been certifying? wouldn't you have been certifying? wouldn't they have been certifying?