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.
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) | — |
Compare every difficulty tier → · A study plan for this tier →
Canonical class-hours and weeks are the FSI figures for this tier, from the US State Dept FSI list (public domain), verified June 2026. How we compile this — confirm against state.gov on an operator pass. Speaker counts, language-family and region data from Wikipedia (Ethnologue figures), licensed CC BY-SA 4.0.