Unfortunately examples of bad translations are all around us and contain some or all of the following:

:: Over-literal translation that sounds stilted, unnatural, even comical
:: Style of writing that isn't appropriate to the subject matter
:: No attempt to adapt to target country/culture/readership
:: Misinterpretation
:: Typos and missing accents
:: Grammatical errors …

How?

:: Machine translation programs - All languages, although logical to an extent, are also extremely complex and subtle. Many people don’t realise that translation software can totally ‘botch up’ translations. Only skilled “human” linguists produce quality translations!

:: Unqualified translators - Language students, a colleague posted abroad, an Italian acquaintance. Being a native, speaking a language, having language qualifications – none of these makes a translator. Good translators are skilled professionals.

:: The “Can’t you just translate the words?” mentality

:: The “Quick and cheap” mentality

:: Inadequate preparation and checking
     
Don't worry, this isn't the g&b way