On many occasions, the whole set of connotations of a word in one language simply cannot be conveyed in another. One such example would be the statement Espero in Spanish. In English, this could be translated in several ways, but the three main options would be as follows:
1) I wait
2) I expect
3) I hope
The translator firstly finds themselves forced to interpret which version the original writer might have intended to communicate, as all three cannot be succinctly retained in English. Secondly, meanwhile, they're consequently obliged to remove any ambiguity that the original might (or might not) have sought to play on among those three potential meanings. And thirdly, the verb esperar is loaded with the same three etymological, social and emotional connotations that cannot be conveyed in English by a single word.
In other words, for instance, when a Spaniard expects something, they're linguistically aware that they're also hoping and waiting for it. An English speaker is not. No matter how we dress up a translator's syntactic and semantic dance, how can such tensions ever be resolved to any degree of satisfaction, how can the same ambiguities and multiplicities of meaning be preserved?