How Many Words Do You Need To Be Fluent In Japanese?

One of the most popular teaching approaches that language learning companies are using these days is one the focuses heavily on acquiring a large vocabulary. So how many words do you need to be fluent in Japanese?

It’s a good question to ask because it can give you a solid language learning goal to work towards achieving each and every day.

I think that in order to come to a satisfying answer, we have to take a couple of things into consideration.

I’m going to talk about a few things when it comes to the number of words people know, and then draw a conclusion that can help you in your studies.

How Many Words Does A Native Know?

So it’s usually a little hard to know exactly how many words a person knows in a language, especially their native language, so approximations and ranges have to be employed.

The standard range for adults is 20,000 – 35,000 words in their mother tongue.

This huge number is what is known as “passive vocabulary” because a person can recognize and understand these words when they encounter them.

On the other hand, the words that a person not only understands, but uses regularly are a part of their “active vocabulary.”

The reason why it’s important to distinguish between these two is because when it comes to learning a second language, the fastest way to achieve fluency is to focus on learning the words that will naturally become a part of your active vocabulary for that language.

Now there are several definitions for what “fluency” is in a language, but the general consensus is that a person is fluent when they can communicate easily and accurately in the target language.

How many words do you need in order to do that?

What Is The Magic Vocabulary Number?

When you think about the rather small amount of words that are needed on a day to day basis for communication, you begin to realize that fluency is vastly different from an adult level command of a native language.

Think about a four year old kid who can communicate with friends and family with few problems.

They know approximately 5,000 words [source] and even though they still make the occasional grammar mistake, for all intents and purposes they are fluent!

By the way, I’ve said nothing about literacy at this point. You can be fluent without knowing how to read Japanese!

Isn’t 5,000 words a lot more manageable than 35,000?

This fact has often lead people who want to become fluent quickly to the conclusion that you should study the top 2,000 frequently used words first in order to gain the maximum benefit from your study time.

This would allow you to reach the point of easy communication among natives, and from there you can expand the amount of words you know gradually.

It’s a smart way to go about it, and it reveals something that is pretty interesting, which is this:

Having a large vocabulary helps, but is not necessary for fluency.

This is because there are additional factors besides the words themselves that are required to understand a language. Some of these things are grammar, and others are simply a mastery of the words you know.

I’m sure I don’t need to go into too much detail right now on these, as grammar is the “glue” that holds complete sentences together, and there is obviously a difference in skill when a person has used a word 10 times compared to when they’ve used it 100 times (or 1,000!).

The 1,000 – 2,000 word range is what most polyglots (people who know several languages) aim for when they take on a new language.

Unfortunately, the number of Japanese words you will need is actually a bit higher than this.

Do you know why?

Why Is The Number Higher For Japanese?

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I think there are a couple of reasons why you need to know more words in Japanese to reach fluency when compared to others (English for example).

From my own experiences, I believe this to be true for two reasons:

  1. The different levels of formality in Japanese.
  2. The high level of precision in the Japanese language.

Let me illustrate each one of these with some actual English and Japanese words.

(1) – The different levels of formality in Japanese.

In English, for the most part, we use the same words when we are talking to our friends or our superiors.

For example, regardless of who asked you the question “When will Mr. Smith come to visit us?” your answer would be “Mr. Smith already came on Monday.”

But this one answer uses different words in Japanese depending on the social status of the person you’re talking to.

(I will color the words that change)

If it was to someone close to you, or of a lower status you would say:

  • スミスさんはもう月曜日に来た

If it was to someone of equal status like a coworker, you would say:

  • スミスさんはもう月曜日に来ました

And if it was to someone higher than you like the company president, you would say:

  • スミスさんは既に月曜日にいらっしゃいました

Each time something changes. Sometimes it’s simply a different form of the same verb, but other times it’s a completely different word that still means the same thing.

So to wrap up reason #1: Japanese has multiple words where other languages only have a single word and the reason is because the different Japanese words show varying levels of respect towards the listener.

(2) – The high level of precision in the Japanese language.

One of the things that I was shocked to discover was just how much gets lost during translation for manga and anime!

A simple example of this is the singular pronoun “I” in English. There are a ton of them in Japanese and they all have a slightly difference nuance!

There’s not enough time to go into all of them, so let me just give you four:

私 – gender neutral, polite

僕 – (usually) used by boys, casual

あたし – used by young girls, casual

俺– used by men, rough

Or how about the English word “wear” as in “what should I wear to school today?”

In Japanese there are several different words and it all depends upon what part of the body the clothing goes onto:

被る – to wear (on one’s head)

着る – to wear (on one’s torso)

履く – to wear (on one’s lower body)

Once you begin learning all of these different words, it becomes obvious why you have to know a larger amount of words for Japanese in order to hit that fluency number.

If Not A Large Vocabulary, Then What Is Needed?

Generally speaking, you need to know about 3,000 – 5,000 Japanese words to be fluent in the language.

But it can’t just be any words, as you could simply learn the names of people, places, and Pokémon to hit one or two thousand.

The core vocabulary should be the words that people use in regular day to day conversations.

You can pick this up rather naturally by speaking with (or just listening to) natives, by reading lots of books in Japanese, by watching anime that’s centered around school life, and so on.

But in addition to that, you need to have a working knowledge of the grammar of the language.

By “working” I mean that you can conjugate verbs, or inflect adjectives into the desired state in a swift and natural manner.

This doesn’t mean treating Japanese like a math equation such as:

  1. First take the verb in its masu-form and remove the masu
  2. Now you have the root, and you can then add tai to it
  3. Since tai is actually an i-adjective, you inflect it as such
  4. So you then remove the final i in tai and replace it with kunakatta
  5. Now you’re ready to use the word!

Rather it means that when you think, “I didn’t want to eat it” in English, and you want to say it in Japanese, you just go straight to “食べたくなかった” without going through that whole 5-step process I explained earlier.

See, you’ve used this Japanese word enough so that you don’t need to start at the base and conjugate/inflect it all the way down from the base to its final form according to the rules.

You simply know that “didn’t want to eat” = 「食べたくなかった」 and you use it instantly.

The way to get to this point is simply by getting lots of exposure to the conjugated/inflected forms of words, and practicing them over and over again.

Fluency is Not The End, It’s Actually The Beginning!

Most people set fluency as their end goal with learning a language, but it’s actually more like a second beginning.

At first you know nothing, and so you want to get to the point where you can use the language fairly easily in your life.

But as I’ve explained, it’s actually a shorter journey to this level of skill than most people think.

Once you reach that point however, you get to work on attaining a native adult’s command of the language, if you want to.

This would mean that you can not only communicate what you need to, but you can understand and enjoy pretty much everything that you come into contact with.

This would be like, being as good at Japanese as you currently are in your native tongue!

13 thoughts on “How Many Words Do You Need To Be Fluent In Japanese?”

  1. As a french native speaker, the 83.5% for 1000 words doesn’t surprise me. In fact, in nearly all (conversational) sentences, we have those pronouns repeated : “je, tu, il, elle, nous, vous, ils, de, des, un, le, la, les, ce, cet, cette, ces, que ………”.

    For example, in the sentence “Il faut que je le voie un de ces quatre.” you would know 70% of the sentence by knowing those words alone, but you wouldn’t even get a grasp of what it means. These words are nearly always there, do not add real meaning, and make the percentage go up.

    In japanese, less words are filler words since there is no pronouns in the french/english sense, and less repetitions (context language).

    So, I think those stats show how much words you understand in the sentence for 1000 words known, but don’t measure actual understanding with 1000 words (that would be hard to tell).
    Moreover, I’m not even sure particles are taken into account when calculating the Japanese 60.5%, but I’m pretty sure french pronouns which have the same role are, because they are actual words.

    So if japanese is difficult, I’d think it’s because of the lack of common roots, rather than a number of words “to know”.

    However, I think your article shows well that levels of formality and precision add some difficulty to learning japanese, and some words to know as well. So it’s indeed true, but not like the 23% gap between french and japanese, I’d think.

    I didn’t make a lot of research, so that’s just my feeling here.

  2. A year long study by a Tokyo newspaper found the following:

    100 40%
    200 57%
    500 80%
    1,000 98%
    2,000 99.7%
    3,000 99,97%
    If you know the 1,000 most common words you can read 98% of the paper.

    • I’m betting that was actually the number of kanji you need to know to read the paper. I’ve been keeping track of the number of words and kanji I’ve added to my vocabulary. I’ve learned over 750 words but only 275 kanji, and my reading comprehension for the newspaper is more in line with the percentage if the quantity represents the number of kanji known by the reader rather than words. I expect someone who knows 1,000 kanji has a teenager-level command of the language based on how many words are written as combinations of kanji.

  3. Dear Nick,

    Interesting article you wrote. Just wanna share my feelings. I have been learning Japanese for about 10 months. Until now it feels daunting. Or should I say it gets more daunting the more I learn. Sometimes I feel I improve pretty well when I’m able to construct a simple sentences rather quickly and I’m able to understand very simple conversation from materials designed for basic beginners. The disappointment comes when I watch a program in Japanese, or when I venture into something else other than my usual beginner materials. That’s when I can’t help but feel I know so little. I’m probably able to catch only 5 or 10% of what’s being said, along with some individual words I recognize. But it’s all too sporadic and fast for me to be able to piece together to make any sense. Thanks for reading!

    • Hey Yusuf, I know exactly how you feel!

      I’ve heard multiple people describe the Japanese language as “endless” and the more I learn, the more I think they are right.

      What I can tell you is that it does get easier the longer you stick with it. For whatever reason, it seems like the human brain (or at least mine) takes in a lot of information without really showing any change in comprehension. Then all of the sudden it feels like you just “jump to a higher level” and your understanding seems to go from 20% to 30% in a single day.

      Perhaps the brain needs some time to make the necessary connections that lead to understanding. I don’t really know.

      One thing that you can start doing right now that I believe will help you is to get the actual transcripts of the show’s dialog and combine reading it with listening to it. This will allow you to look up the specific words and phrases that they are using, which should help your comprehension greatly.

      Thanks for sharing your thoughts!

      • I never studied Japanese yet, And am honestly hesitant to start learning Japanese, because all I know it’s a very difficult language to learn and that I speak arabic (mother tongue) n English that’s 2 major languages of this world and for that I can agree to what you have just said coz the same thing happened to me when I started to learn English, it was hard and I always felt after knowing many words that I can’t understand or even speak them correctly, But, as u said maybe this is how our brains work especially when we don’t live in the language environment. But then with consistency as if I kept smashing that stiff chain that’s holding the gate of the garden I started to speak fluently in 2 weeks all of a sudden! And everything I’ve learned and even maybe forgot started to show up during the chats n convos! And the feeling was awesome as if you just tamed a big monster and willingly became your friend!

        • Yeah, I totally get what you’re saying. Many times while I was learning Japanese it felt like all I did was struggle without making progress, but then one day you just “get it” and are able to read or converse comfortably.

          If you’re curious about learning Japanese then I highly encourage you to try it out. It is a really fun language!

    • Active immersion, comprehensible input. There’s a whole community of people learning languages where these two concepts are the rule. On YouTube you can find them like Matt vs Japan, Immerse with Migaku, and others. Don’t give up man, go out there and learn 日本語!

    • In language learning, there is a rule called 80/20. What that means is that, if you learn 20% of a language’s vocabulary, you will speak with 80% fluency. Let’s say that an average Japanese adult knows an average of 25,000 words. If you learn 10,000 words, you’ll survive a conversation 4 out of 5 times.

      In reality, it’s more like 95/5, as long as the words you have learned are the most frequently used words.

      I recommend everyone buy a book of the most commonly used words for the language they are learning. I bought a book of the 2,000 most commonly used words in Japanese, along with various books on grammar, verb conjugation and particles, and kana and kanji flashcards and workbooks. I’m just starting out on my journey, but I am hoping for TV level fluency in about 6 months by approaching language learning from the perspective of learning the most frequently used first. If you master a few thousand of the most commonly used words, then you’ll achieve the level of comprehension of spoken media that you are aiming for.

      Good luck!

  4. I agree that you do not need to know how to read a language to be fluent. Some people get so fixated on “knowing it all” when being able to get by is really all that is required.

    If you move to the country that speaks a different language, you won’t be able to help getting better and better at it. I know because my brother lived in Japan for a year with the Navy and when he brought home a Japanese fiance, they were arguing in Japanese a lot (it didn’t work out)!

    Also, thank you for breaking down sentence structure. This is the most important part of sentences. If you use them in the wrong order, a completely different meaning would be gleaned compared to what you were trying to say.

    • Hey Ernest, that’s a really good point you made. 

      There’s no need to learn everything, but rather you should focus on learning the information that will be the most useful to you. 

      Then when you are in an environment where you are immersed in the language, be it a self-created environment or you’re actually in Japan, the knowledge you’ve gained up until that point will work as a launch pad for your abilities to improve.

      Immersion at the beginning is probably too much and not super helpful, but once you’ve got a solid base of understanding and you can learn new things from context, then immersion becomes a godsend! 


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