Which one of the following is not an official language of the United Nations ?

The United Nations has six official languages: Arabic, Chinese, English, French, Russian, and Spanish [t1][t3]. These languages are used for official documents and during UN meetings, where speeches are simultaneously interpreted into all six [t2][t5]. While English and French were the original working languages of the Secretariat, all six are now considered both official and working languages [t5][t8]. Portuguese is not an official language of the United Nations, although it is recognized as a geographically diverse language and the second most spoken Romance language after Spanish [t7]. The selection of the six official languages was based on their global relevance and the populations they represent, covering approximately 2.8 billion people [t2][t5]. Therefore, among the given options, Portuguese is the one that does not hold official status within the UN system.

Sources

1. [1] https://www.un.org/en/our-work/official-languages