According to an urban legend, Kennedy allegedly made an embarrassing grammatical error by saying "Ich bin ein Berliner," referring to himself not as a citizen of Berlin,  but as a common pastry
Kennedy should have said "Ich bin Berliner" to mean "I am a person from Berlin." By adding the indefinite article ein, his statement implied he was a non-human Berliner, thus "I am a jelly doughnut".
The legend seems to stem from a play on words with Berliner, the name of a doughnut  variant filled with jam or plum sauce that is thought to have originated in Berlin.
In fact, Kennedy's statement is both grammatically correct and perfectly idiomatic, and would not be misunderstood in context. The urban legend is not widely known within Germany, where Kennedy's speech is considered a landmark in the country's postwar history.  The indefinite article ein can be and often is omitted when speaking of an individual's profession or residence but is necessary when speaking in a figurative sense as Kennedy did.  Since the president was not literally from Berlin but only declaring his solidarity with its citizens, "Ich bin Berliner" would not have been correct.

The origins of the legend are obscure. The
Len Deighton spy novel Berlin Game  published in 1983, contains the following passage, spoken by narrator Bernard Samson.
'Ich bin ein Berliner,' I said. It was a joke. A Berliner is a doughnut. The day after President Kennedy made his famous proclamation, Berlin cartoonists had a field day with talking doughnuts.

The New York Times review of Deighton's novel added the detail that Kennedy's audience found his remark funny


----- Original Message -----
From: "robert meyer" <[log in to unmask]>
To: [log in to unmask]
Subject: Re: T.S.E. at 101
Date: Mon, 19 Jan 2009 23:38:46 -0800

Gunnar?  Huh?!?  I lived in Germany in the mid 1960s, and the Germans always referred to a citizen of a city as whatever the city's name was plus a suffix of "er" - citizens of Frankfurt were "Frankfurters", citizens of Berlin were "Berliners", citizens of Hamburg were "Hamburgers."  Only in America Frankfurters are sausages, Berliners are jelly rolls, and Hamburgers are fried meat patties; Americans just make up weird words.  I had never heard the word Berliner as referring to jelly roll until years after that when I was in an American grocery store and saw a box of pastries called "Berliners" and thought, "how strange" - but that was in America, not Germany.  Then in the 1980s, I heard that story on a tabloid TV show called "A Current Affair" hosted by Maury Povich (and owned by none other than that erudite scholar, Rupert Murdoch).  After that, the story took off like wild-fire and everybody was ta! lking about it, saying, "it must be true, it's on TV."  
Robert Meyer
----- Original Message -----
From: [log in to unmask] href="mailto:[log in to unmask]">Gunnar Jauch
To: [log in to unmask] href="mailto:[log in to unmask]">[log in to unmask]
Sent: 1/19/2009 6:13:48 PM
Subject: Re: T.S.E. at 101

Sorry, dear Carrol -- I've mixed up JFK's stuff with Obama's -- a Freudian slip!
Just goes to show how much of a projection of hope he was in Europe at the time

 "Ich bin ein Berliner" -- a statement JFK delivered in front of hundreds of thousands of people in besieged Berlin at the time,
never realizing that, in German, a "Berliner" means a doughnut...

I still remember lots of jokes about that at the time!