English verb conjugation
OUGHT TO ASCERTAIN

Regular verb: ascertain - ascertained - ascertained

Affirmation

Simple form	V-ing form
I ought to ascertain you ought to ascertain he ought to ascertain we ought to ascertain you ought to ascertain they ought to ascertain	I ought to be ascertaining you ought to be ascertaining he ought to be ascertaining we ought to be ascertaining you ought to be ascertaining they ought to be ascertaining
Perfect	V-ing perfect
I ought to have ascertained you ought to have ascertained he ought to have ascertained we ought to have ascertained you ought to have ascertained they ought to have ascertained	I ought to have been ascertaining you ought to have been ascertaining he ought to have been ascertaining we ought to have been ascertaining you ought to have been ascertaining they ought to have been ascertaining

Negation

Simple form	V-ing form
I oughtn't to ascertain you oughtn't to ascertain he oughtn't to ascertain we oughtn't to ascertain you oughtn't to ascertain they oughtn't to ascertain	I oughtn't to be ascertaining you oughtn't to be ascertaining he oughtn't to be ascertaining we oughtn't to be ascertaining you oughtn't to be ascertaining they oughtn't to be ascertaining
Perfect	V-ing perfect
I oughtn't to have ascertained you oughtn't to have ascertained he oughtn't to have ascertained we oughtn't to have ascertained you oughtn't to have ascertained they oughtn't to have ascertained	I oughtn't to have been ascertaining you oughtn't to have been ascertaining he oughtn't to have been ascertaining we oughtn't to have been ascertaining you oughtn't to have been ascertaining they oughtn't to have been ascertaining

Interrogative form

Simple form	V-ing form
ought to I ascertain? ought to you ascertain? ought to he ascertain? ought to we ascertain? ought to you ascertain? ought to they ascertain?	ought to I be ascertaining? ought to you be ascertaining? ought to he be ascertaining? ought to we be ascertaining? ought to you be ascertaining? ought to they be ascertaining?
Perfect	V-ing perfect
ought to I have ascertained? ought to you have ascertained? ought to he have ascertained? ought to we have ascertained? ought to you have ascertained? ought to they have ascertained?	ought to I have been ascertaining? ought to you have been ascertaining? ought to he have been ascertaining? ought to we have been ascertaining? ought to you have been ascertaining? ought to they have been ascertaining?

Interro-negative form

Simple form	V-ing form
oughtn't I to ascertain? oughtn't you to ascertain? oughtn't he to ascertain? oughtn't we to ascertain? oughtn't you to ascertain? oughtn't they to ascertain?	oughtn't I to be ascertaining? oughtn't you to be ascertaining? oughtn't he to be ascertaining? oughtn't we to be ascertaining? oughtn't you to be ascertaining? oughtn't they to be ascertaining?
Perfect	V-ing perfect
oughtn't I to have ascertained? oughtn't you to have ascertained? oughtn't he to have ascertained? oughtn't we to have ascertained? oughtn't you to have ascertained? oughtn't they to have ascertained?	oughtn't I to have been ascertaining? oughtn't you to have been ascertaining? oughtn't he to have been ascertaining? oughtn't we to have been ascertaining? oughtn't you to have been ascertaining? oughtn't they to have been ascertaining?