I may ascertain you may ascertain he may ascertain we may ascertain you may ascertain they may ascertain
V-ing form
I may be ascertaining you may be ascertaining he may be ascertaining we may be ascertaining you may be ascertaining they may be ascertaining
Perfect
I may have ascertained you may have ascertained he may have ascertained we may have ascertained you may have ascertained they may have ascertained
V-ing perfect
I may have been ascertaining you may have been ascertaining he may have been ascertaining we may have been ascertaining you may have been ascertaining they may have been ascertaining
Negation
Simple form
I mayn't ascertain you mayn't ascertain he mayn't ascertain we mayn't ascertain you mayn't ascertain they mayn't ascertain
V-ing form
I mayn't be ascertaining you mayn't be ascertaining he mayn't be ascertaining we mayn't be ascertaining you mayn't be ascertaining they mayn't be ascertaining
Perfect
I mayn't have ascertained you mayn't have ascertained he mayn't have ascertained we mayn't have ascertained you mayn't have ascertained they mayn't have ascertained
V-ing perfect
I mayn't have been ascertaining you mayn't have been ascertaining he mayn't have been ascertaining we mayn't have been ascertaining you mayn't have been ascertaining they mayn't have been ascertaining
Interrogative form
Simple form
may I ascertain? may you ascertain? may he ascertain? may we ascertain? may you ascertain? may they ascertain?
V-ing form
may I be ascertaining? may you be ascertaining? may he be ascertaining? may we be ascertaining? may you be ascertaining? may they be ascertaining?
Perfect
may I have ascertained? may you have ascertained? may he have ascertained? may we have ascertained? may you have ascertained? may they have ascertained?
V-ing perfect
may I have been ascertaining? may you have been ascertaining? may he have been ascertaining? may we have been ascertaining? may you have been ascertaining? may they have been ascertaining?
Interro-negative form
Simple form
mayn't I ascertain? mayn't you ascertain? mayn't he ascertain? mayn't we ascertain? mayn't you ascertain? mayn't they ascertain?
V-ing form
mayn't I be ascertaining? mayn't you be ascertaining? mayn't he be ascertaining? mayn't we be ascertaining? mayn't you be ascertaining? mayn't they be ascertaining?
Perfect
mayn't I have ascertained? mayn't you have ascertained? mayn't he have ascertained? mayn't we have ascertained? mayn't you have ascertained? mayn't they have ascertained?
V-ing perfect
mayn't I have been ascertaining? mayn't you have been ascertaining? mayn't he have been ascertaining? mayn't we have been ascertaining? mayn't you have been ascertaining? mayn't they have been ascertaining?