What Is the Hardest Language to Learn? Top 10 List

Ever wondered why some people can pick up Spanish in a few weeks, but struggle for years to make even modest progress with Mandarin or Arabic?

The answer is that not all languages are equally easy to learn for native English speakers… even for people who are naturally good at learning languages.

So, what language is the hardest to learn?

Read on for a breakdown of the top 10 most difficult languages to learn, what makes them so difficult, and how you can use AI to make life a lot easier if you’ve decided to take one on.

TL: DR – Languages like Mandarin, Arabic, and Japanese can take years for native English speakers to master thanks to tricky grammar rules, unfamiliar tones, and new alphabets. Becoming fluent isn’t impossible, but it requires time, consistency, and a willingness to embrace a completely different culture.

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Key Takeaways

• Mandarin, Arabic, Japanese, and Korean are the hardest languages for English speakers to learn.

• The FSI ranks these as Category IV languages, requiring around 2,200+ study hours for fluency.

• Complex grammar, new alphabets, and tonal pronunciation make them especially challenging.

• Cultural context and idiomatic expressions often lack direct English translations.

• AI tools like Paraphraser, Translator, and Grammar Checker can simplify learning complex rules.

• Consistency, immersion, and cultural exposure are key to mastering difficult languages.

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How Language Difficulty Is Measured

According to the U.S. Foreign Service Institute (FSI), language difficulty is best measured by the number of hours it takes to reach fluency, grouping languages into the following five categories:

• [Easiest] Category I, taking an estimated 24-30 weeks to learn.
• [Moderate] Category II, taking an estimated 36 weeks to learn.
• [Hard] Category III, taking an estimated 44 weeks to learn.
• [Super Hard] Category IV, taking an estimated 88 weeks to learn.

Top 10 Hardest Languages for English Speakers to Learn

So, what is the hardest language to learn for English speakers?

According to the FSI, the following 10 category III and category IV languages are among the toughest languages for English speakers.

1. Mandarin Chinese (Category IV)

Even though it’s one of the most widely spoken languages in the world, Mandarin tops almost every list as one of the most difficult languages to learn for native English speakers.

Here’s why:

• Writing System and Vocabulary: Instead of an alphabet, you’ll need to learn thousands of unique characters. Plus, Mandarin doesn’t use noun classes or plural forms in the same ways English does.
• Tones: Mandarin is a tonal language, meaning the same words can have completely different meanings depending on the pitch of your voice.
• Cultural Context: Idioms and sayings often don’t translate literally, making it harder for learners with little experience with the culture to grasp.

2. Cantonese (Category IV)

Cantonese, which is spoken in Hong Kong, southern China, and among overseas Chinese communities, is another Category IV language because of the following:

• Tones: If you thought Mandarin was difficult with four tones, Cantonese has six to nine (depending on how you count them).
• Characters: Uses traditional Chinese characters, which are often more complex than the simplified ones used in Mandarin.
• Pronunciation: Many sounds don’t exist in English, making it difficult to hear and reproduce accurately.

3. Arabic (Category IV)

Arabic is spoken across dozens of countries in the Middle East, but each region has its own variations.

Here’s what makes the Arabic language so difficult to learn.

• Alphabet and Words: Written right to left.
• Dialects: Egyptian Arabic, Gulf Arabic, Levantine Arabic.
• Pronunciation: A lot of guttural sounds and new sounds (like “ʿayn”), which don’t exist in English.

4. Japanese (Category IV)

At first glance, Japanese might seem similar to Chinese because of its kanji characters, but it does have its own quirks, including:

• Three Writing Systems: Kanji (characters), hiragana, and katakana; all used interchangeably.
• Grammar: Word order and particles are completely different from English.
• Formality Levels: Politeness levels change depending on who you’re speaking to.

5. Korean (Category IV)

The Korean language has its own alphabet (Hangul), which isn’t known for being too difficult to memorize.

However, everything else about this language can be a real challenge for English speakers.

• Grammar: Subject-object-verb structure, honorifics, and lots of different verb endings.
• Vocabulary: Few cognates with English.
• Formality Levels: You can’t speak the same way to your professor as you would to your friend.

6. Hungarian (Category III)

Although it’s a European language, it’s one of the most difficult to learn for the following reasons:

• Cases: Over 18 different cases affect nouns.
• Vocabulary: Not closely related to other European languages.
• Pronunciation: Unfamiliar sounds and long compound words.

7. Finnish (Category III)

Finnish is often ranked alongside Hungarian as a nightmare for native English speakers.

Here’s why:

• Cases: Around 15 cases to memorize.
• Word Formation: Words can be extremely long due to agglutination (i.e., adding multiple endings to a root word).
• Pronunciation: Double vowels and consonants can change the meaning of a word entirely.

8. Icelandic (Category III)

Icelandic is only spoken by around 300,000 people, and it’s notoriously difficult for English speakers because of:

• Grammar: Complex case systems and verb patterns.
• Vocabulary: New words are created from Old Norse roots, not borrowed from English.
• Pronunciation: Long compound words and unique sounds.

9. Polish (Category III)

Another European language that’s tricky to learn, known for its consonant clusters and unpredictable spelling rules.

• Cases: Seven grammatical cases.
• Consonant Clusters: Words like przszczyna are difficult to pronounce.
• Spelling Rules: Lots of exceptions, and subtle accent marks can completely change the meaning of a word.

10. Greek (Category III)

Greek might look friendlier than other languages on this list, but it’s still one of the most difficult languages for English speakers because of its:

• Alphabet: Completely different from the Latin alphabet.
• Grammar: Complex verb conjugations and noun cases.
• Language Development: Even though English borrows a lot of words from ancient Greek, modern usage of the language isn’t always intuitive or beginner-friendly.

Full List of Category III and IV Languages According to FSI

Unfortunately, these 10 languages aren’t the only languages that are difficult for English speakers. Here’s a full list of the FSI’s Category III and Category IV languages.

Category III and IV Languages (According to the U.S. Foreign Service Institute)
	Languages	Estimated # of Weeks to Learn
Category IV	Arabic, Cantonese, Mandarin, Japanese, and Korean	88 Weeks
Category III	Albanian, Amharic, Armenian, Azerbaijani, Bengali, Bosnian, Bulgarian, Burmese, Croatian, Czech, Estonian, Finnish, Georgian, Greek, Hebrew, Hindi, Hungarian, Icelandic, Khmer, Lao, Latvian, Lithuanian, Macedonian, Mongolian, Nepali, Pashto, Persian, Polish, Russian, Serbian, Sinhala, Slovak, Slovenian, Tagalog, Thai, Turkish, Ukrainian, Urdu, Uzbek, Vietnamese, Xhosa, and Zulu	44 Weeks

Why These Languages Are Difficult

So what is it that actually makes a category III and category IV language so difficult?

Typically, it comes down to the following:

• New Alphabets or Character Systems: Instead of the Latin alphabet, level III and VI languages often use entirely different alphabets, like the Cyrillic alphabet (used in Russian, Ukrainian, and Bulgarian) or logographic systems (like Chinese and Japanese).
• Unfamiliar Sounds and Pronunciations: The tonal systems used in languages like Mandarin, Cantonese, and Arabic are completely different from English. For example, a single change in pitch can alter a word’s meaning entirely. This adds an extra layer of difficulty, even for new learners who can memorize vocabulary perfectly.
• Cultural Differences: Idioms and ways of expressing ideas in languages like Japanese or Arabic often don’t have a direct English equivalent.
• Complex Grammar Systems: The most difficult languages often use grammar structures that are completely foreign to English speakers.

Pro Tip: If you’re learning a category III or category IV language, tools like Ask AI can help you get to grips with complex grammar rules, so you can start applying them to your writing or assignments ASAP.

Easier vs Harder Comparisons

So, how do the hardest languages stack up against some of the easiest languages to learn?

Check out the table below for examples and estimations on learning timelines.

Easiest vs Hardest World Languages to Learn as a Native English Speaker
Category	Languages	Why It’s Easy/Hard	Estimated Study Time to Achieve Fluency
Category I(Easiest)	Germanic languages and Romance languages that use the Latin script, like Spanish, French, Italian, and Dutch	Share Latin/Germanic roots with English.Familiar grammar patterns, overlapping vocabulary with English words, and similar word endings.	552-690 hours (24–30 weeks)
Category II(Moderate)	German, Swahili, Indonesian	More complex grammar than Category I, but still fairly accessible for native English speakers with similar Grammar structures and (some) vocabulary.	828 hours (36 weeks)
Category III	Albanian, Amharic, Armenian, Azerbaijani, Bengali, Bosnian, Bulgarian, Burmese, Croatian, Czech, Estonian, Finnish, Georgian, Greek, Hebrew, Hindi, Hungarian, Icelandic, Khmer, Lao, Latvian, Lithuanian, Macedonian, Mongolian, Nepali, Pashto, Persian, Polish, Russian, Serbian, Sinhala, Slovak, Slovenian, Tagalog, Thai, Turkish, Ukrainian, Urdu, Uzbek, Vietnamese, Xhosa, and Zulu	Grammar systems, sounds, and writing styles are significantly different from English.	1,012 hours (44 weeks)
Category IV–V(Hardest)	Mandarin, Arabic, Japanese, Korean	Completely different writing systems, tones, honorifics, grammar structures, and cultural contexts.	2200+ hours (88 weeks)

How to Overcome the Challenge of Learning Complex Languages

Looking to take on a difficult language?

Here are a few quick tips for setting yourself up for success:

• Stay Consistent: Practicing for just 5-10 minutes a day is far more effective than cramming in an hour or two once a month.
• Take Advantage of AI Tools: Tools like our AI Paraphraser allow you to see how words and grammar systems can work in different contexts. Other tools like Grammar Checker and Translator can help you polish your writing for assignments (or chats with friends across the world).
• Immerse Yourself in the Culture: Watch movies, listen to music, and read as many books (even children’s books) as possible. The more you surround yourself with a new language, the easier it is to learn.

Frequently Asked Questions About the Most Difficult Languages to Learn

Final Thoughts: Is Learning a Difficult Language Worth It?

If you want to learn a second language and love a challenge, choosing a category III or IV language to learn can be one of the most rewarding things you’ll ever do.

Yes, Mandarin, Arabic, or Hungarian may demand thousands of hours of study, but the payoff is worth it.

You’ll sharpen your memory and problem-solving skills, learn to love a completely different culture, and earn the bragging rights that come with mastering one of the world’s most difficult languages.

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