“How long will it take me to learn this language?” It’s one of the first questions new students ask. The most trusted answer comes from the U.S. government. The Foreign Service Institute (FSI) trains American diplomats, and it has published estimates based on decades of classroom experience. These FSI language difficulty rankings group languages by how long English speakers usually need to reach professional proficiency on the ILR scale.
Here’s how the categories work, what they actually measure, and how to use them to plan language training.
What Is the FSI Language Difficulty Ranking?
The FSI’s School of Language Studies trains U.S. government employees who need a language for their jobs. Over the years, it has tracked how long students take to reach a specific goal. That goal is “General Professional Proficiency,” or a score of Speaking-3/Reading-3 (S-3/R-3) on the Interagency Language Roundtable (ILR) scale.
In other words, a learner at that level can handle most professional and social conversations with confidence. They can also read general professional material without much difficulty. Because FSI defines its goal in ILR terms, these rankings translate directly to ILR-based training. For more on what each level means, see our guide to the ILR scale.
Based on that data, FSI sorts languages into four categories. In short, FSI language difficulty reflects training time, not how hard a language feels. You can see the full list on the State Department’s foreign language training page
The Four FSI Language Difficulty Categories
| Category | Typical Training Time | Example Languages |
|---|---|---|
| I | 24–30 weeks (600–750 class hours) | Danish, Dutch, French, Italian, Norwegian, Portuguese, Romanian, Spanish, Swedish |
| II | About 36 weeks (900 class hours) | German, Haitian Creole, Indonesian, Malay, Swahili |
| III | About 44 weeks (1,100 class hours) | Farsi, Hebrew, Hindi, Russian, Tagalog, Turkish, Vietnamese, and many more |
| IV | 88 weeks (2,200 class hours) | Arabic, Cantonese, Mandarin, Japanese, Korean |
Category I covers languages similar to English. Most take about 24 weeks, while French and Spanish take closer to 30.
Category II is a small group. German shares roots with English, but its grammar adds time. Indonesian, Malay, and Swahili use the Latin alphabet, but most of their vocabulary is unfamiliar to English speakers.
Category III is the largest group by far. FSI calls these “hard languages” because they have significant linguistic or cultural differences from English. The list runs from Albanian to Vietnamese, and FSI notes that it still isn’t exhaustive.
Category IV includes the five “super-hard” languages. They take about twice as long as Category III languages, so planning ahead matters. Many of them also appear on U.S. critical language lists. As a result, trained speakers are in high demand.
What Makes a Language Difficult for English Speakers?
No language is hard in absolute terms. After all, children everywhere learn their native language naturally. Instead, difficulty depends on how far a language sits from the one you already speak. For English speakers, a few factors tend to add the most time.
- Writing systems: Learning a new script takes time. Mandarin and Japanese characters, in particular, require years of steady practice.
- Sounds and tones: Tonal languages like Mandarin, Cantonese, and Vietnamese use pitch to change meaning. Similarly, other languages include sounds that English doesn’t have at all.
- Grammar: Features like noun cases, verb aspect, and honorific speech levels can take a long time to master.
- Vocabulary: Spanish and French share thousands of related words with English. By contrast, Korean and Arabic offer far fewer familiar words to build on.
- Culture: FSI’s own definition of a “hard language” includes cultural differences. Politeness norms, indirect communication, and social hierarchy all shape how people actually speak. Therefore, language training works best alongside cross-cultural preparation.
Why FSI Timelines Are Averages, Not Guarantees
FSI is clear that its language difficulty estimates reflect average results. Actual time varies based on a learner’s natural ability, prior language experience, and time spent in the classroom.
Prior experience matters more than many people expect. For example, someone who already speaks Spanish will often learn Portuguese faster. We explore this in our post on whether you can learn languages faster if you already know similar ones.
It’s also worth remembering who FSI’s students are. They’re adult professionals studying full-time, with a clear job-related goal. However, most learners don’t train under those conditions. In addition, the FSI goal covers speaking and reading only. So listening and writing may develop at a different pace.
Turning FSI Class Hours Into a Real Schedule
However, FSI language difficulty figures assume intensive, full-time study. In fact, 600 class hours over 24 weeks works out to about 25 class hours a week.
Part-time learning, by contrast, looks very different. At five class hours a week, 600 to 750 hours would take about two and a half to three years. Meanwhile, 2,200 hours at that pace would take more than eight years.
Part-time learners also tend to need extra hours overall, since skills fade between sessions. That’s one reason intensive or semi-intensive formats are so common for high-stakes goals. Even so, steady part-time study still builds real skills, especially with regular practice outside class.
Using FSI Language Difficulty to Plan Training
For organizations preparing employees for new roles, FSI language difficulty is a practical planning tool. Here’s how to put it to work:
- Set realistic targets. Reaching S-3/R-3 in Korean requires far more time than it does in Spanish. Also, not every role needs Level 3. A goal of ILR 2 or 2+ generally takes less time, while 3+ and above take considerably more.
- Build in lead time. For Category III and IV languages, start training well before an assignment or relocation begins.
- Choose the right intensity. Full-time training reaches goals fastest. Part-time training fits busy schedules but stretches the timeline.
- Start with a placement assessment. Many learners already have some ability, so an accurate starting level keeps training efficient.
- Plan for sustainment. Language skills decline without use. However, short maintenance courses can help protect the investment.
- Pair language with culture. The harder the language, the wider the cultural gap tends to be. Cultural training therefore helps learners use their new skills effectively.
How DLS Helps Learners Reach Their Goals
Since 1985, DLS has provided language and cultural training to government employees, business clients, and private students. We offer full-time and part-time courses in over 85 languages, across all four FSI categories. We also customize each course to the student’s goals and schedule.
Whatever your language’s difficulty category, we measure progress on the ILR scale, the same scale behind the FSI timelines. Our courses cover every stage, from initial acquisition to maintenance and enhancement. As a result, learners and managers always know where they stand. You can also read how DLS complements FSI training for the foreign affairs community.
Planning language training for yourself or your team? Contact us to build a program around your language, timeline, and proficiency goals.
