The book: The New Guide of the Conversation in Portuguese and English written by Pedro Carolino and José da Fonseca in 1855. Although, it's probably better known by its 1883 edition title, English As She Is Spoke.
Mistake #1: becomes side-splittingly clear the second you open the book. Let's just say the entire thing reads like a particularly bad cheating attempt by a junior high schooler using Babelfish. According to the text, some common phrases a Portuguese traveler might use in England include: "That are the dishes whose you must be and to abstain;" "These apricots and these peaches make me and to came water in the mouth;" and the always-familiar idiom, "The stone as roll heap up not foam." It's this sort of high-quality translating work that made the book the world's first ironic bestseller - even prompting Mark Twain to contribute a preface to a later edition.
Mistake #2: became the stuff of legend. For decades, most experts have believed that Carolino and da Fonseca agreed to write an English phrasebook, despite the fact that neither knew English. Nor did they have access to a Portuguese-English dictionary. Instead, they wrote English As She Is Spoke using first a Portuguese-French dictionary and then a French-English one.
Mistake #3: was only recently discovered. In 2002, a graduate student at UCLA unveiled a new theory that José da Fonseca had been unfairly maligned by history. Apparently a legit scholar, da Fonseca had published a number of respectable translations and language guides - including an 1836 Portuguese-French phrasebook that bears a striking resemblance to English As She Is Spoke. The difference? Da Fonseca's book actually makes sense. According to the new research, Pedro Carolino simply came along 19 years later, poorly translated da Fonseca's French into English, then slapped both their names on the finished product.
mental_floss, March-April 2007, mentalfloss.com
