In 1897, the editor of the New York Sun made a famous contribution to Santa Claus lore with his famous editorial Yes, Virginia, there is a Santa Claus (from Newseum and Wikipedia). But his reasoning can be applied more generally.

Type in the name of some entity or entities, then select with the popups the words that grammatically agree with it. When you are ready, press "Let's See It!"

Yes, Virginia, there is a is an is the is are are the ,
who is a boy a girl both neither .
"Not believe in a an the (...)?"