Problems text source:

• Misspelled or misprinted text
• Changes made to the text during the translation process
• Incomplete text
• Poorly written text (ambiguity or incomprehensibility)
• Obvious inaccuracies in the source text
• Missing references in the text
• Illegible or difficult-to-read text
• The source text contains a translation of a quotation that was originally made in the target language, and the original text is unavailable, making true quoting nearly impossible

Other

• Rhymes, poetic meters, and puns
• Humour
• Highly specific cultural references
• Insider information
• Words commonly known in one culture but unknown by the layperson in another culture.
• Subtle but important properties of language such as dissonance or euphony

Many times common words are a problem for translation because if they have several meanings in the original language it may be very difficult for translators to tell which words should be used in the translated-to language. This, obviously, lend to translation error or ambiguity.

Then there are many ‘untranslatable’ word and sayings in many languages where finding an equivalent in another language is at least difficult if not the target of intense debate as to how best translate the word or phrase in question.

Here are some more translation articles...