I can preascertain you can preascertain he can preascertain we can preascertain you can preascertain they can preascertain
Forme en V-ing
I can be preascertaining you can be preascertaining he can be preascertaining we can be preascertaining you can be preascertaining they can be preascertaining
Perfect
I can have preascertained you can have preascertained he can have preascertained we can have preascertained you can have preascertained they can have preascertained
Perfect en V-ing
I can have been preascertaining you can have been preascertaining he can have been preascertaining we can have been preascertaining you can have been preascertaining they can have been preascertaining
Négation
Forme simple
I cannot preascertain you cannot preascertain he cannot preascertain we cannot preascertain you cannot preascertain they cannot preascertain
Forme en V-ing
I cannot be preascertaining you cannot be preascertaining he cannot be preascertaining we cannot be preascertaining you cannot be preascertaining they cannot be preascertaining
Perfect
I cannot have preascertained you cannot have preascertained he cannot have preascertained we cannot have preascertained you cannot have preascertained they cannot have preascertained
Perfect en V-ing
I cannot have been preascertaining you cannot have been preascertaining he cannot have been preascertaining we cannot have been preascertaining you cannot have been preascertaining they cannot have been preascertaining
Forme interrogative
Forme simple
can I preascertain? can you preascertain? can he preascertain? can we preascertain? can you preascertain? can they preascertain?
Forme en V-ing
can I be preascertaining? can you be preascertaining? can he be preascertaining? can we be preascertaining? can you be preascertaining? can they be preascertaining?
Perfect
can I have preascertained? can you have preascertained? can he have preascertained? can we have preascertained? can you have preascertained? can they have preascertained?
Perfect en V-ing
can I have been preascertaining? can you have been preascertaining? can he have been preascertaining? can we have been preascertaining? can you have been preascertaining? can they have been preascertaining?
Forme interro-négative
Forme simple
can I not preascertain? can you not preascertain? can he not preascertain? can we not preascertain? can you not preascertain? can they not preascertain?
Forme en V-ing
can I not be preascertaining? can you not be preascertaining? can he not be preascertaining? can we not be preascertaining? can you not be preascertaining? can they not be preascertaining?
Perfect
can I not have preascertained? can you not have preascertained? can he not have preascertained? can we not have preascertained? can you not have preascertained? can they not have preascertained?
Perfect en V-ing
can I not have been preascertaining? can you not have been preascertaining? can he not have been preascertaining? can we not have been preascertaining? can you not have been preascertaining? can they not have been preascertaining?