This page comprises a list of 736 "essentialist explanations" of the form "Language X is essentially language Y under conditions Z".

For instance, English:

English is essentially bad Dutch with outrageously pronounced French and Latin vocabulary.
--Eugene Holman

English is essentially Norse as spoken by a gang of French thugs.
--Benct Philip Jonsson

English is essentially Anglo-Saxon with all the cool bits taken out.
--Thomas Leigh

English is essentially Dutch but it doesn't want to admit it.
--Danny Wier

English is essentially Pictish that was attacked out of nowhere by Angles cohabiting with Teutons who were done in by a drunk bunch of Vikings masquerading as Frenchmen who insisted they spoke Latin and Greek but lacked the Arabic in which to convey that.
--Bill Hammel

English is essentially all exceptions and no rules.
--Jonathan Bettencourt

There are also entries for French, Spanish, Italian, German, Welsh just for Jennifer, and many many others. I guess this joke is more or less like "The Aristocrats" for comparative linguistics; now the secret's out.

(My personal favorite variant of this joke is "if _____ and _____ had a baby." Occassionally "...raised by _____." I use it all the time.)

(via Boing Boing)