This is why translation accuracy will vary across languages. The more human-translated documents that Google Translate can analyze in a specific language, the better the translation quality will be.
Since the translations are generated by machines, not all translation will be perfect. This process of seeking patterns in large amounts of text is called “statistical machine translation”. By detecting patterns in documents that have already been translated by human translators, Google Translate can make intelligent guesses as to what an appropriate translation should be. Google Translate is a third-party service provided by Google that performs all translations directly and dynamically.