Which UN Language Should You Learn? The Six Compared

If you want to learn one of the six official UN languages, the choice comes down to three things: how many people you'll be able to talk to, how long it will take you, and what you actually want to do with it. Here are the six side by side, with numbers from sources you can check.

This post assumes you already speak English. If you don't, English is almost certainly the answer, and you can skip to the last section.

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The six at a glance

Speaker figures are from Ethnologue's 2026 (29th) edition as reported by Wikipedia and Visual Capitalist. *Ethnologue counts Modern Standard Arabic as nobody's first language: people grow up speaking Egyptian, Levantine, Gulf or another variety and learn the standard at school. Each spoken variety is counted separately, so the Arabic total understates how many people speak some Arabic.

FSI hours are the U.S. Foreign Service Institute's class-hour estimates for an English speaker to reach professional working proficiency, roughly upper B2 to low C1. They exclude homework. Our FSI categories guide explains what they measure.

Spanish: the most reach per hour

Spanish is FSI Category I, 30 weeks or about 690 class hours, and it has more native speakers than any UN language except Mandarin. For an English speaker, no other UN language gives you this many people for this little time. It's also the most practical in the Americas, including much of the United States.

French: the diplomatic pick

French is also 690 hours, with a much smaller native base (75 million) but a large second-language population across West and Central Africa, plus official status in Canada, Belgium and Switzerland. It is one of the two working languages of the UN Secretariat, along with English, and it is an official language of most international bodies; see our list of languages of international organizations. If your goal is a career in diplomacy or international development, French usually beats Spanish.

Russian: the middle option

Russian sits in FSI Category III at about 1,012 class hours: Cyrillic is quick to learn, the case system is not. It is still widely used across Central Asia and the Caucasus. Pick it for regional interest, literature or work in that part of the world rather than for raw speaker count.

Arabic and Mandarin: the long road

Both are FSI Category IV at 88 weeks, about 2,200 class hours, three times Spanish. They are hard for different reasons.

• Arabic asks you to learn two things: Modern Standard Arabic for reading, news and formal speech, and at least one spoken variety for everyday conversation. Decide early which variety you want, because it changes your materials. More in our Arabic tracking guide.
• Mandarin has tones and characters but very little inflection. Speaking gets going sooner than reading does. Our Mandarin hours guide breaks the 2,200 down.

The payoff is scarcity. Far fewer English speakers reach a working level in these two, so the skill stands out more on a CV.

How long would it take you?

Pick a language and how much you study each day. The calculator uses FSI's figures; switch the goal to B1 for a rough conversational target (about half the FSI hours).

A simple way to decide

• Most people for the least time: Spanish.
• UN, NGOs, diplomacy, Africa: French.
• A rare, valued skill and you have years: Arabic or Mandarin.
• Eastern Europe and Central Asia: Russian.
• You don't speak English yet: English, the largest language on Earth by total speakers and the UN Secretariat's main working language.

The best predictor of success is still whether you keep showing up, so pick the one you'll want to spend time with. If you're tempted by more than one, read how many hours all six would take first, and how to choose your next language for a broader framework.

FAQ

What is the easiest UN language for English speakers?

Spanish and French. The U.S. Foreign Service Institute puts both in Category I at 30 weeks, about 690 class hours, to professional working proficiency. Russian is about 1,012 hours; Arabic and Mandarin are about 2,200.

Which UN language has the most speakers?

English, with about 1.49 billion total speakers in Ethnologue's 2026 edition. Mandarin has the most native speakers, about 988 million.

Which UN language is most useful for working at the UN?

English or French, because they are the working languages of the UN Secretariat. A second official language counts in your favour, but one of those two is the baseline.