Umberto Eco is a writer, theorist, critic and translator of renown. He has this to say about translation:
The job of translation is a trial and error process, very similar to what happens in an Oriental bazaar when you are buying a carpet. The merchant asks 100, you offer 10 and after an hour of bargaining you agree on 50.Given the essential instability of the tokens of exchange in the translation market, the more crucial the integrity of their original minting - i.e. the need to choose the word that most closely matches your specific thought.
Translation, in fact, takes place at its original stage entirely within the individual. The process is this. The individual has a thought and wants to express it. Both in oral and written expression, there is a process that the individual goes through -- in its extreme form, experienced when writing as writer's block and in speech as stage fright -- which involves a negotiation between the idea and one's store of words & phrases. In other words, translation occurs between idea and word. This can also be described as a translation between inner and outer: between one's ideas & intentions and then the one's interloctor(s)' s understanding.
In this also, the specificity of the word is vital. The challenges are great: as indicated in this article -- or, perhaps better, this audio essay - by Jesse Sheidlower, an Editor-at-Large for the Oxford English Dictionary, in which he argues that "literally" is not to be used literally. (For what [little] it is worth, I think the argument is misguided, though cogent and erudite.)