It is commonly believed that translators are better at translating into their native language than into a second language. The underlying reason for this assumption is that translators have a more profound linguistic and cultural background of their mother tongue than of a second language which they have to learn in order to be well-versed translators. By the same token, the translator who translates into his or her native language has a more natural and practical knowledge of the various linguistic elements of his or her native language, such as semantics, syntax, morphology and lexicology than the translator who translates into a foreign language.
In addition, translation into the first language enables translators to render cultural elements such as proverbs, idioms, metaphors, collocations, swear words and others into proper equivalents in their mother tongue because such translators are born and bred in the culture into which they translate these culture-bound aspects. In fact, the translators' first language is naturally acquired in a culture and environment where the first language is naturally acquired and practiced. On the other hand, their second language is, for the most part, learned, rather than acquired, later on in the course of their life. As a result, the linguistic and cultural knowledge of their second language is always in progress and never complete. In this respect, James Dickins (2005) points out: