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