I should preascertain you should preascertain she should preascertain we should preascertain you should preascertain they should preascertain
V-ing form
I should be preascertaining you should be preascertaining she should be preascertaining we should be preascertaining you should be preascertaining they should be preascertaining
Perfect
I should have preascertained you should have preascertained she should have preascertained we should have preascertained you should have preascertained they should have preascertained
V-ing perfect
I should have been preascertaining you should have been preascertaining she should have been preascertaining we should have been preascertaining you should have been preascertaining they should have been preascertaining
Negation
Simple form
I should not preascertain you should not preascertain she should not preascertain we should not preascertain you should not preascertain they should not preascertain
V-ing form
I should not be preascertaining you should not be preascertaining she should not be preascertaining we should not be preascertaining you should not be preascertaining they should not be preascertaining
Perfect
I should not have preascertained you should not have preascertained she should not have preascertained we should not have preascertained you should not have preascertained they should not have preascertained
V-ing perfect
I should not have been preascertaining you should not have been preascertaining she should not have been preascertaining we should not have been preascertaining you should not have been preascertaining they should not have been preascertaining
Interrogative form
Simple form
should I preascertain? should you preascertain? should she preascertain? should we preascertain? should you preascertain? should they preascertain?
V-ing form
should I be preascertaining? should you be preascertaining? should she be preascertaining? should we be preascertaining? should you be preascertaining? should they be preascertaining?
Perfect
should I have preascertained? should you have preascertained? should she have preascertained? should we have preascertained? should you have preascertained? should they have preascertained?
V-ing perfect
should I have been preascertaining? should you have been preascertaining? should she have been preascertaining? should we have been preascertaining? should you have been preascertaining? should they have been preascertaining?
Interro-negative form
Simple form
should I not preascertain? should you not preascertain? should she not preascertain? should we not preascertain? should you not preascertain? should they not preascertain?
V-ing form
should I not be preascertaining? should you not be preascertaining? should she not be preascertaining? should we not be preascertaining? should you not be preascertaining? should they not be preascertaining?
Perfect
should I not have preascertained? should you not have preascertained? should she not have preascertained? should we not have preascertained? should you not have preascertained? should they not have preascertained?
V-ing perfect
should I not have been preascertaining? should you not have been preascertaining? should she not have been preascertaining? should we not have been preascertaining? should you not have been preascertaining? should they not have been preascertaining?