The hardest language in the world? What learning times really show
Arabic, Japanese, Chinese? Where the famous list of hard languages comes from, what it actually measures – and why your own languages matter most.
Contents
Where does the list of “hard” languages come from?
Search for the hardest language and you will almost always end up at the same source: the Foreign Service Institute (FSI), the US State Department's language school. Based on its experience, it sorts languages into four categories. What it measures is how many weeks of training its students usually need to reach a score of 3 in speaking and listening on the US government's ILR scale.[1] That level is called “General Professional Proficiency”: being able to take part effectively in most formal and informal conversations on practical, social and professional topics.[5] A typical FSI week has 23 hours of class and 17 hours of self-study.[1]
| Category | Weeks | Examples (selection from the FSI list) |
|---|---|---|
| I – “close to English” | 24–30 | Dutch, Italian, Portuguese (24 each), Spanish, French (30 each) |
| II | approx. 36 | German, Indonesian, Malay, Swahili |
| III – “hard languages” | approx. 44 | Russian, Polish, Turkish, Persian, Hindi, Urdu, Greek, Vietnamese |
| IV – “super-hard languages” | 88 | Arabic, Chinese (Mandarin and Cantonese), Japanese, Korean |
The list is meant honestly, but it has a catch that is often left out: it describes how hard a language is for native speakers of English. FSI explicitly calls category I “languages close to English” and category IV “exceptionally difficult for native English speakers”.[1] For speakers of other languages the ranking looks different – for a native speaker of German, German itself is obviously not a category II language.
What makes a language hard?
In short: distance. The more a new language differs from the languages you already know, the more you have to learn from scratch. Researchers measure this distance at several levels, and several large data sets show the same pattern:
- Vocabulary and grammar: In an analysis of speaking tests in Dutch – taken by adults with many different first and second languages – the distances in vocabulary and word formation (morphology) between the first language and Dutch explained 47.7% of the differences in scores.[2]
- Vocabulary, forms and sounds: In the average TOEFL scores of over 15 million learners of English from 127 countries with 65 first languages, greater linguistic distance was consistently associated with lower scores.[3]
- Pronunciation: Among immigrants in the US and in Germany, a distance measured by comparing the pronunciation of word lists went along with weaker self-reported language skills – especially at the start.[4]
Then there is the script. It is striking that none of the category IV languages is written in the Latin alphabet.[1] Learning Arabic, Chinese, Japanese or Korean therefore means learning not just new words and rules, but learning to read and write all over again. What that looks like for Arabic is covered in Is Arabic hard to learn?
And if English isn't your first language?
There is no list like the FSI's for native speakers of German, Turkish or Arabic. But research on linguistic distance shows what matters: closeness to the languages you already know. Dutch, for example, is closely related to German; that German speakers recognise a lot of it is no coincidence.
And it is not only your first language that counts. In the Dutch study, learners' second languages made a difference too: the distances between their second language and Dutch explained 32.4% of the differences in speaking scores among multilingual learners.[2] So if you already speak English well, you bring more to the next language than just your first language.
Hard doesn't mean out of reach
A large distance makes the start harder. What happens after that is less clear-cut. In the study of immigrants in Germany, people with more “distant” first languages caught up in German over time; the initial disadvantage shrank. In the US data from the same study, the opposite showed: there the paths tended to drift apart.[4]
FSI also stresses that actual learning time varies – with natural ability, prior experience with languages and time spent in class.[1] So the 88 weeks for Arabic or Japanese are not a verdict but a planning figure: it takes longer, and that is normal.
Which language should you learn?
The easiest language is the one you don't give up after three weeks. The data tell you what to expect – not what to learn. If you need a particular language for family, faith, travel or work, distance is no reason against it, only a reason for more patience.
Sources
The numbers in square brackets in the text point to this list.
- U.S. Department of State, Foreign Service Institute. Foreign Language Training. state.gov (accessed 22 Oct 2026)Experience figures from the US State Department’s language school: weeks to a score of 3 (speaking + listening) on the ILR scale; 23 hours of class + 17 hours of self-study a week. For category IV the stated 2,200 hours don’t quite match 23 hours × 88 weeks – so we give the weeks.
- Schepens JJ, Van der Slik FWP, van Hout RWNM (2016). L1 and L2 Distance Effects in Learning L3 Dutch. Language Learning 66(1), 224–256Speaking test scores in Dutch of adults with many different first and second languages; observational. Read: abstract.
- Van der Slik FWP, van Hout RWNM (2025). Linguistic distance effects on country TOEFL scores between 2005 and 2020 and the effect of morphological distance in particular. Second Language ResearchAverage TOEFL scores of over 15 million learners from 127 countries with 65 first languages, 2005–2020; country level, observational. Read: abstract.
- Isphording IE, Otten S (2014). Linguistic barriers in the destination language acquisition of immigrants. Journal of Economic Behavior & Organization 105, 30–50Immigrants in the US (American Community Survey, 514,874 observations) and Germany (Socio-Economic Panel, 5,803 person-years); self-reported language skills; observational. Read: manuscript (full text).
- Interagency Language Roundtable. ILR Skill Level Descriptions for Speaking. govtilr.orgOfficial description of the US government scale; level 3 = “General Professional Proficiency”.
How this article was made
Translated from German with AI assistance. Researched and drafted with the help of AI, then checked claim by claim against the sources listed before publication. The cover is an AI-generated illustration. Responsible: Inan Software OG, Vienna. Found a mistake? Write to support@limny.app – corrections are listed with their date below the article.
