I can certify you can certify she can certify we can certify you can certify they can certify
Forme en V-ing
I can be certifying you can be certifying she can be certifying we can be certifying you can be certifying they can be certifying
Perfect
I can have certified you can have certified she can have certified we can have certified you can have certified they can have certified
Perfect en V-ing
I can have been certifying you can have been certifying she can have been certifying we can have been certifying you can have been certifying they can have been certifying
Négation
Forme simple
I cannot certify you cannot certify she cannot certify we cannot certify you cannot certify they cannot certify
Forme en V-ing
I cannot be certifying you cannot be certifying she cannot be certifying we cannot be certifying you cannot be certifying they cannot be certifying
Perfect
I cannot have certified you cannot have certified she cannot have certified we cannot have certified you cannot have certified they cannot have certified
Perfect en V-ing
I cannot have been certifying you cannot have been certifying she cannot have been certifying we cannot have been certifying you cannot have been certifying they cannot have been certifying
Forme interrogative
Forme simple
can I certify? can you certify? can she certify? can we certify? can you certify? can they certify?
Forme en V-ing
can I be certifying? can you be certifying? can she be certifying? can we be certifying? can you be certifying? can they be certifying?
Perfect
can I have certified? can you have certified? can she have certified? can we have certified? can you have certified? can they have certified?
Perfect en V-ing
can I have been certifying? can you have been certifying? can she have been certifying? can we have been certifying? can you have been certifying? can they have been certifying?
Forme interro-négative
Forme simple
can I not certify? can you not certify? can she not certify? can we not certify? can you not certify? can they not certify?
Forme en V-ing
can I not be certifying? can you not be certifying? can she not be certifying? can we not be certifying? can you not be certifying? can they not be certifying?
Perfect
can I not have certified? can you not have certified? can she not have certified? can we not have certified? can you not have certified? can they not have certified?
Perfect en V-ing
can I not have been certifying? can you not have been certifying? can she not have been certifying? can we not have been certifying? can you not have been certifying? can they not have been certifying?