I may preascertain you may preascertain she may preascertain we may preascertain you may preascertain they may preascertain
V-ing form
I may be preascertaining you may be preascertaining she may be preascertaining we may be preascertaining you may be preascertaining they may be preascertaining
Perfect
I may have preascertained you may have preascertained she may have preascertained we may have preascertained you may have preascertained they may have preascertained
V-ing perfect
I may have been preascertaining you may have been preascertaining she may have been preascertaining we may have been preascertaining you may have been preascertaining they may have been preascertaining
Negation
Simple form
I mayn't preascertain you mayn't preascertain she mayn't preascertain we mayn't preascertain you mayn't preascertain they mayn't preascertain
V-ing form
I mayn't be preascertaining you mayn't be preascertaining she mayn't be preascertaining we mayn't be preascertaining you mayn't be preascertaining they mayn't be preascertaining
Perfect
I mayn't have preascertained you mayn't have preascertained she mayn't have preascertained we mayn't have preascertained you mayn't have preascertained they mayn't have preascertained
V-ing perfect
I mayn't have been preascertaining you mayn't have been preascertaining she mayn't have been preascertaining we mayn't have been preascertaining you mayn't have been preascertaining they mayn't have been preascertaining
Interrogative form
Simple form
may I preascertain? may you preascertain? may she preascertain? may we preascertain? may you preascertain? may they preascertain?
V-ing form
may I be preascertaining? may you be preascertaining? may she be preascertaining? may we be preascertaining? may you be preascertaining? may they be preascertaining?
Perfect
may I have preascertained? may you have preascertained? may she have preascertained? may we have preascertained? may you have preascertained? may they have preascertained?
V-ing perfect
may I have been preascertaining? may you have been preascertaining? may she have been preascertaining? may we have been preascertaining? may you have been preascertaining? may they have been preascertaining?
Interro-negative form
Simple form
mayn't I preascertain? mayn't you preascertain? mayn't she preascertain? mayn't we preascertain? mayn't you preascertain? mayn't they preascertain?
V-ing form
mayn't I be preascertaining? mayn't you be preascertaining? mayn't she be preascertaining? mayn't we be preascertaining? mayn't you be preascertaining? mayn't they be preascertaining?
Perfect
mayn't I have preascertained? mayn't you have preascertained? mayn't she have preascertained? mayn't we have preascertained? mayn't you have preascertained? mayn't they have preascertained?
V-ing perfect
mayn't I have been preascertaining? mayn't you have been preascertaining? mayn't she have been preascertaining? mayn't we have been preascertaining? mayn't you have been preascertaining? mayn't they have been preascertaining?