Books from so many countries are now published in English that it is highly unlikely any publishing house will have editors that are fluent in all the languages. The most important thing is that a book being published in English should be edited in English, because this is the language in which the book is being read. Martin Riker believes that the editor’s primary concern must be towards the quality of the work in English, so that it creates for an English-language reader an experience approximate to the experience the book’s original readers had. The editor first and foremost must be a reader of English, and a person for whom the translation must read, in English, like an original work— which in many senses it is.
Knowledge of the language in question can, however, be an advantage, particularly at the copyediting stage. Some people suggest that a copyeditor should read a translation line-by-line against the original book but this seems an extravagant and unnecessary effort. The copyeditor’s job is to ensure that the book works in its own right, rather than as a faithful translation. However, when things don’t seem to be working, it can be useful for an editor to check the original source text to see if there is an easy solution, or if an error has been made.
Ultimately, though, editors must trust a good translator, and assume that every effort has been made to translate accurately. Queries can be addressed to the translator, who will have made decisions about every word choice and can defend or explain their use. It’s very likely that a translator will already have consulted the author about issues that are unclear, or areas where there is some confusion, and so he or she will be in a position to explain or justify.
Read: Paul G: Finding the Right Translator
Reference
Paul, Gill. (2009). Translation in practice. Champaign and London: Dalkey Archive Press