Why is Idiom Translation Challenging?
Translation involves more than simply substituting a word in one language for another. If this was the case, then all companies would be using automatic translation software, instead of using human based translation services. In translation, there are grammar rules to be followed to preserve the meaning of the original content.
Translators that are native speakers of the target language (the language that you’re translating to) can easily adhere to grammar rules. However, the same cannot be said about idioms.