Lack of semantic equivalents among languages

Nature

The process of translation, whether human or machine-assisted, is unable to generate a text that is completely equivalent semantically between source language and target language, except in the simplist of cases. It is notably impossible to respect rhythm, sound symbolism, puns, and cultural allusions. The absence of semantic equivalence can give rise to dangerous forms of misunderstanding.

Counter-claim

Exact equivalence is not even possible when paraphrasing within a single language. There is always some loss of information. There are however many kinds of inexact equivalence, any of which can be successful at a certain level of practical functioning.