When people start thinking about learning a language like Russian or Chinese, one of the first thoughts that spring to mind is that it would be way too difficult. You should not dismiss the idea of learning a particular language just because it is generally considered hard (if you are truly motivated to learn it, you will eventually reach fluency), but the idea that some languages are harder to learn than others is, unfortunately, correct.
How hard it is to learn a particular foreign language for you depends on many different factors, such as natural talent, available learning resources, and your learning plan, but I believe that the single most important factor is how closely related the language is to the languages you already speak.
Since this article is written in English, I will concentrate on the difficulty of learning various languages for monolingual English speakers. If you already speak another language, this will make other languages from the same language group much easier to learn, especially in terms of vocabulary.
Difficulty of learning vocabulary
English vocabulary is a mixture of words coming mostly from Germanic languages, French, Latin, and Greek. As a result, adjectives in English are often not derived from the corresponding nouns but rather from words originating in a different language, for example:
ten – decimal
end – final
There are many others. While this feature is not so good for English learners (they have to learn more words than necessary), it is very helpful for English speakers who learn Romance and Germanic languages. It will be easy for you to remember that “hand” is Hand in German and mano in Spanish, that “ten” is tien in Dutch and dieci in Italian, or that “end” is Ende in German and fin in French.
However, different languages share different amounts of vocabulary with English. If I should rank languages according to the difficulty of learning vocabulary for a monolingual English speaker, the list would probably go as follows:
|Difficulty of learning vocabulary|
Dutch, Afrikaans, and closely related Germanic languages
Lots of basic words (common verbs, nouns, and adjectives) look or sound similar. Dutch has a significant number of French loanwords that were also borrowed into English.
Esperanto, Interlingua, and similar constructed languages
These languages were artificially designed to be easy to learn for speakers of European languages (they use mainly roots that exist in several language families). The majority of roots should be intelligible to an English speaker without prior exposure.
French, Spanish, Italian, Portuguese, Romanian, and other Romance languages
Most of basic vocabulary is completely different, but technical and scientific vocabulary is almost identical to English. If your goal is to understand formal written materials (especially scientific writing), Romance languages may actually be easier than Dutch or Afrikaans.
Latin vocabulary is somewhat less intelligible to an English speaker than that of modern Romance languages, mainly because the topics you will read about are completely unrelated to modern lifestyle and technology. Still, you will be able to recognize a fair number of words right away.
Just like in Dutch, there are many similarities in basic vocabulary, but the overall number of similar words is smaller. You will have to learn a system of prefixes and suffixes that is quite different from the English one.
Swedish, Norwegian, Danish (but Icelandic is more difficult)
Many basic words are similar, but their spelling and pronunciation have drifted even further away from English than they did in German. There are also quite a few loanwords from French you will recognize.
Polish, Czech, Slovak, Croatian, and other Slavic languages written using the Latin alphabet
Almost none of the most common words share common roots with English. There are borrowings from Latin, French and English in technical vocabulary, but almost everything else will be completely new.
Russian, Ukrainian, Bulgarian, and other Slavic languages written with the Cyrillic script
The same note as above applies to these languages, but with the added layer of difficulty of having to use a different alphabet (which makes similar words even less recognizable).
A nontrivial amount of English technical vocabulary comes from Greek, but the number of borrowings is much smaller than in the case of Romance languages. The vast majority of words will not look familiar at all (and you will have to master a new alphabet), but you will still understand a word every now and then.
Hindi and other Indic languages
Hindi is an Indo-European language, which means that it shares some similarities with European languages. Spoken Hindi tends to employ a large number of English loanwords, which will make it more readily intelligible than Slavic languages. However, these words tend to be replaced by Sanskrit words in formal Hindi, making it less intelligible.
These two closely related languages (with more than 250 million speakers in total) contain a decent number of loanwords from European languages and use a system of affixes to derive new words, which somewhat simplifies the process of learning new vocabulary.
Arabic, Korean, Hungarian, Finnish, and pretty much every other language (except Chinese and Japanese (see below), Indo-European languages not mentioned above, and other languages significantly influenced by European languages)
While there are a few English loanwords in those languages, learning their vocabulary will remind you of learning an alien language. Finnish and Hungarian have a few more loanwords due to their geographic proximity to European languages, but it is still not enough to give you any good point of reference.
Some people would argue that Arabic should be in the next category (because “there are 300 different words just for a camel”), but the fact is, the number of different words actually used by people or the media is not larger than in any other language, and it has a system of roots that makes learning new vocabulary a tiny bit easier.
Again, European loanwords are relatively scarce. However, the situation with Chinese and Japanese is further complicated due to their writing system (you will have to learn around 2,200 characters to be able to read and write Japanese and 3,500 characters to read and write Chinese). Doing this is an extremely difficult task, and even the majority of educated native speakers never fully master the Chinese and Japanese writing system.
Difficulty of learning grammar
Even though English shares a lot of words with other European languages, its grammar is quite unique. There are no grammatical genders (inanimate objects being treated as male or female), no noun declensions (nouns do not change according to their function in a sentence), virtually no conjugations (most English verbs have only four different forms, e.g. walk, walks, walked, and walking, while verbs in French can have over 40 different forms!), no endings for adjectives depending on gender, and the list could go on.
This makes it harder for English speakers to understand various common grammatical constructions in other European languages. Nevertheless, not all languages contain the same amount of features that are missing in English. Here is my (perhaps somewhat subjective) list of languages ordered by difficulty of mastering their grammar systems:
|Difficulty of learning grammar|
Afrikaans has an extremely simple grammar. Verbs are not conjugated according to person or number; e.g. “I am, you are, he is” translates to “ek is, jy is, hy is”. Other tenses are almost entirely regular. There are no grammatical genders.
Chinese (Mandarin, Cantonese, and most other varieties)
Chinese grammar is extremely simple. Verbs are not conjugated and nouns are not declined. Even pronouns have only one form (there is no distinction between “I” and “me”, and “my” is basically translated as “of I”). Chinese does not even have tenses; they are understood implicitly from the context.
Whether Indonesian grammar should be considered easy depends mainly on whether you consider its complex system of infixes, suffixes, and infixes part of its grammar or part of its vocabulary. The rules of syntax are simple: there are no grammatical genders, no verb conjugation, and the word order is similar to English.
Esperanto, Interlingua, and similar constructed languages
Unsurprisingly, languages designed to be easy are easy. Both Esperanto and Interlingua have no grammatical genders. Verbs are not conjugated according to person and number and all tenses are formed in a regular way using suffixes (except three irregular verbs in Interlingua).
Dutch, Swedish, Norwegian, Danish
These languages are grammatically very similar to English. However, they have two grammatical genders (Dutch has three in some varieties), and you have to remember the gender of every noun to use articles and adjectives correctly. There are also lots of irregular plurals.
What makes Dutch stand out as slightly more complicated than the rest (but not much) is its system of verb conjugation. In Swedish, Norwegian, and Danish, verbs are not conjugated according to person and number (just like in Afrikaans). In Dutch they are, and there are some irregularities that have to be memorized. All four languages have a fair amount of irregular past tense forms (just like English, and some are reminiscent of their English counterparts).
French, Spanish, Italian, Portuguese, Romanian
The main problem with the grammars of Romance languages is their verb and tense system. A single verb in French, for example, can have up to 40 different forms (conjugated according to tense, number, and person). Verbs fall into 3 or 4 broad classes, and there are a large number of irregular verbs. Some tenses and moods (especially the subjunctive) are notoriously hard to master for English speakers.
The languages have two genders (or three in the case of Romanian), and articles and adjectives have to agree in gender and number with the nouns they modify. In Romanian, this is further complicated by the existence of a case system for nouns (it is necessary to learn two different sets of endings, one for the nominative/accusative case and one for the genitive/dative).
There are three grammatical genders in German and four cases. Articles and adjectives are declined according to gender, number, and case, giving 16 forms in total that have to be memorized (and there are two different ways to decline adjectives, depending on whether they are are used in a “definite” or “indefinite” way).
German has a relatively simple tense system (there are much fewer verb forms than in Romance languages), but most verbs are irregular in one way or another. Plurals are commonly irregular. Some other parts of German grammar, such as word order and separable/inseparable prefixes, also cause problems.
Hindi has two genders and three cases. Nouns and adjectives are declined according to gender, number, and case, and the system is comparable to German in terms of difficulty. The verb system is fairly regular and not very complex.
What makes Hindi grammar somewhat difficult is its system of postpositions, which are completely unfamiliar to an English speaker (postpositions are like prepositions, but they come after the noun rather than before).
(Ancient) Greek, Latin
Greek and Latin are basically German on steroids in terms of noun declension combined with a huge system of tenses and verb conjugation (which is somewhat simpler in Modern Greek compared to Ancient Greek). They both have three grammatical genders. Latin has six cases, Ancient Greek has five, and Modern Greek has four. However, unlike German, one gender does not equal one conjugation pattern (paradigm); there are several different paradigms for every gender.
Nouns don’t have grammatical gender, and while there is a respectable number of cases (15), case endings are perhaps easier to learn than in Latin or Greek (there is basically only one paradigm with certain predictable phonological changes). Nevertheless, the system of verb conjugation is relatively complex.
One of the harder things is getting used to the fact that things that are expressed in a different way in Finnish than they are in Indo-European languages. Most ideas are expressed using case endings rather than prepositions, and even those that aren’t are mostly expressed using postpositions (instead of “under the table”, the Finns would say something like “table[genitive] under”).
Russian, Polish, Ukrainian, Czech, Croatian, and other Slavic languages
Slavic languages are hard for reasons similar to Greek and Latin. There are three genders, but also a property called “animacy” (living beings behave grammatically in a way different from inanimate things), giving up to six different gender–animacy combinations (depending on the language). Nouns are declined according to many different paradigms (e.g. 16 in Czech), and many nouns are irregular (one exception is Bulgarian, which has almost entirely lost its case system but makes up for it by having a more complex system of conjugation). There are two types of adjectives (soft and hard), which are declined according to gender and number (and animacy).
Each verb has implicitly one of two (or more) different aspects, so verbs have to be memorized in pairs (or more). To understand the notion of aspect, notice the difference between “I went”, “I have gone”, and “I used to go”—these would be three different verbs in the past tense in most Slavic languages. The system of verb conjugation is extensive and full of small irregularities, but it is still simpler than in Romance languages. Most Slavic languages have a complex system of numerals and “free” word order that carries subtle differences in meaning.
Hungarian is similar to Finnish in many ways. It has an extensive system of case endings (up to 18, depending on the definition) and a system of postpositions. The verb system is less complex than in Romance languages, but it has some unfamiliar properties, such as conjugation according to “definiteness” of objects.
The actual amount of memorization needed to master Hungarian grammar is probably smaller than for Slavic languages, but the problem is that the language works in a way significantly different from Indo-European languages. Most notably, it is a topic-prominent language, which means that sentences are structured around topics, not subjects.
Japanese does not have grammatical gender and number, and verb conjugation tends to be fairly regular (but not trivial by any means). It does not have cases, but there is a system of particles placed after words or phrases that function in a way similar to cases in European languages.
Japanese has a very extensive system of honorifics. Every verb has up to four different forms: plain, respectful, humble, and polite. Each form is appropriate in a different social context, and mastering the system is notoriously hard for non-native speakers. Nouns also get honorific prefixes.
Japanese (like Hungarian) is topic-prominent, and its sentence structure is head-final and left-branching, which, simply put, means that whenever something modifies something else, it has to precede it. To give a few examples from Wikipedia: “the man who was walking down the street” translates literally as “street down was walking man”, and “Bob bought his mother some flowers and his father a tie” as “Bob mother for some flowers and father for tie bought”.
Korean is in a way similar to Japanese. It does not have grammatical gender or number, but it does have a system of particles that replace cases. Word order is similar to Japanese and hence completely alien to an English speaker.
Korean system of honorifics is even more complex than the Japanese one. While verbs have only two honorific forms, there are many different suffixes and particles to be used with proper names and pronouns, which depend delicately on the relative social status of the speaker, the subject, and the listener.
Modern Standard Arabic has two genders, three numbers (singular, dual, plural), three states (indefinite, definite, construct), and three cases. Nouns and adjectives are declined according to all of these. There are 8 different declension paradigms, giving some 200 endings that have to be memorized (but there are some overlaps).
The system of verb conjugation is immense. It is based on roots consisting of three (or, less commonly, four or five) consonants. There are 10 basic ways in which vowels and other consonants can be filled in between the root consonants to form verbs (which have related meanings, such as “write”, “dictate”, and “copy”). Every verb has roughly 100 different forms (depending on tense, gender, etc.), and there are differences between the 10 different types of verbs we mentioned. Certain special types of verbs (assimilated, hollow, defective) are conjugated in yet another way.
This is further complicated by the fact that short vowels are usually omitted in the Arabic script. As a result, many verbs and endings look the same in writing but have to be pronounced differently, which makes mastering them by passive exposure to written materials impossible.
Some people would argue that the difficult parts described above are almost non-existent in everyday spoken Arabic (the so-called Arabic “dialects”) and, therefore, you can ignore them. While it is true that spoken varieties are simpler, if you want to be a literate user of Arabic, you will have to learn Modern Standard Arabic at some point (an international standard of Arabic used in the media), which has all the features described above.
Difficulty of learning pronunciation
It would be possible to create a similar list for the difficulty of learning pronunciation, but I believe that it would be rather subjective. Some people tend to be naturally better at pronunciation (some can imitate different accents in their native language easily while others can’t), and your “sound inventory” depends on which part of the English-speaking world you come from (there are large phonological differences between Scottish English and American English, for example).
Pronunciation is rarely a big issue if you receive proper guidance and are regularly exposed to authentic audio materials. If you master other parts of the language (vocabulary and grammar) and use the language actively, it is almost guaranteed that you will be able to make yourself understood, and your pronunciation will naturally improve as you use your target language.
One issue with pronunciation is that some languages are not written phonemically. While French has a reputation of being “non-phonetic”, if you learn the rules, it will still be relatively easy to pronounce words properly, and probably all other European languages have more phonemic orthographies than French. Non-phonemic orthography only really becomes an issue with languages such as Arabic (because short vowels are not written at all) and Chinese and Japanese (which use characters unrelated to how words are pronounced).
Chinese also has a bad reputation because it is a tonal language (there are different types of “intonation” of vowels), but I believe that the difficulty of learning the tones is usually exaggerated. Yes, it is a very foreign concept at first, but it pales in comparison with the difficulty of learning Chinese characters. You can pretty much master the concept of tones in a matter of weeks, but it will take you many years to master the writing system.
It should be noted that English has probably the least phonemic orthography of all languages written with the Latin alphabet, and this is a common source of problems for non-native English speakers (so much that I wrote a whole book about commonly mispronounced English words). Nevertheless, I wrote this article for English speakers, so the difficulty of learning English for speakers of other languages is not discussed here.
Total difficulty of learning
I have presented two different tables, one for vocabulary and one for grammar. I reckon you would probably like to know something about the overall difficulty.
Vocabulary, in my opinion, is the more important part of language learning. Even if you don’t know the rules of grammar very well, you can still make yourself understood (“I be home” is intelligible; “I ??-first-person ??-adverb” is not). You will also be able to consume the language passively (watch a film, read a book) because it is often possible to infer the grammatical function of a word from the context.
Grammar becomes increasingly more important as you try to achieve a higher level of proficiency. In other words, you will progress faster at the beginning if you study a language with “easy” vocabulary, but once the size of your vocabulary becomes decent and you try to get closer to a native-like level, grammar will be the main source of difficulties.