Category IV: ~2200 class hours
The Foreign Service Institute classifies languages into difficulty categories based on the time required for native English speakers to achieve professional working proficiency. Category IV comprises five languages: Arabic, Cantonese, Japanese, Korean, and Mandarin Chinese. The FSI estimates that reaching professional working proficiency in a Category IV language requires 2200 class-hours and 88 weeks of study.
Category IV languages are among the most distant from English in terms of linguistic structure, writing systems, and cultural context. These languages typically feature non-Latin scripts, tonal systems, or grammatical frameworks fundamentally different from English. Notably, the FSI assessment for Category IV assumes in-country immersion, as the time estimates may extend considerably for those studying outside the target language environment. The five languages in this tier represent some of the most challenging acquisition targets for English-speaking learners.
This Category IV (“super-hard”) figure of roughly 2,200 class hours assumes about half of that time is spent studying in-country, in an immersive environment — without immersion, plan for longer.
- Weeks, full-time
- ~88
- Languages in tier
- 5
- Tier
- Category IV
Turning the hours into study
The FSI figure is class hours to professional proficiency — convert it into a sustainable weekly pace, front-load an unfamiliar writing system, and build a daily habit. Casual self-study takes longer than the full-time estimate.
Languages in this tier
| Language | FSI hours | Writing system | FSI harder? |
|---|---|---|---|
| Arabic | ~2200 hrs | Arabic | — |
| Cantonese | ~2200 hrs | Chinese (Traditional) | — |
| Japanese | ~2200 hrs | Kanji + Kana | yes |
| Korean | ~2200 hrs | Hangul | — |
| Mandarin Chinese | ~2200 hrs | Chinese (Simplified/Traditional) | — |
12-week language study planner
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Common questions
How many class hours does an FSI Category IV language take?
About 2200 class hours — roughly 88 weeks of full-time instruction — to reach professional working proficiency, per the US State Department's FSI. This Category IV (“super-hard”) figure of roughly 2,200 class hours assumes about half of that time is spent studying in-country, in an immersive environment — without immersion, plan for longer.
Which languages are in FSI Category IV?
5 of the FSI-taught languages sit in Category IV, including Arabic, Cantonese, Japanese, Korean. The full list is on this page, with each language's own hours page linked.
Compare every difficulty tier → · A study plan for this tier → · All 75 languages ranked →
Canonical class-hours and weeks are the FSI figures for this tier, from the US State Dept FSI list (public domain), used verbatim and last verified June 2026. How we compile and re-verify this data. Speaker counts, language-family and region data from Wikipedia (Ethnologue figures), licensed CC BY-SA 4.0.