may ascertain
Regular verb: ascertain - ascertained- ascertained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I may ascertain
you may ascertain
she may ascertain
we may ascertain
you may ascertain
they may ascertain 	I may be ascertaining
you may be ascertaining
she may be ascertaining
we may be ascertaining
you may be ascertaining
they may be ascertaining	I may have ascertained
you may have ascertained
she may have ascertained
we may have ascertained
you may have ascertained
they may have ascertained	I may have been ascertaining
you may have been ascertaining
she may have been ascertaining
we may have been ascertaining
you may have been ascertaining
they may have been ascertaining	

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

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