Linguist Jürgen Eichhoff, writing in the academic journal Monatshefte, confirms there was no flub on Kennedy’s part. “‘Ich bin ein Berliner’ is not only correct,” he says, “but the one and only correct way of expressing in German what the President intended to say.”
An actual resident of Berlin would say, in proper German, “Ich bin Berliner.” But that wouldn’t have been the correct thing for Kennedy to say. The indefinite article “ein” is added to a statement like this, Eichhoff explains, to express a metaphorical identification between subject and predicate. In fact, “ein” is required in a sentence such as this unless the speaker wants to be taken literally.
For example, the German sentences “Er ist Politiker” and “Er ist ein Politiker” both mean “He is a politician,” but they’re understood by German speakers as different statements. The first means, more exactly, “He is (literally) a politician.” The second means “He is (like) a politician.” You would say of George W. Bush, “Er ist Politiker.” But you would say of an organizationally astute coworker, “Er ist ein Politiker.”
So let’s hear no more of this “jelly doughnut” nonsense.