Note: this page reflects its author's opinion. Although it is a relatively popular one, the arguments made count more than the conclusions. For example, Read The Kanji takes a different approach.
Many languages use a pretty limited set of squiggles for writing. Japanese uses quite an extensive one!
Japanese actually has two sets of squiggles:
In writing, Japanese uses a mix of both. Hiragana get used notably in word endings for conjugation, and for connector words, while kanji are very often used for word roots.
This takes us to the point: when starting with Japanese, learning the few dozen characters of the syllabary is useful, but consider not putting all the kanji in the same category. The closest thing in English would probably be morphemes in etymology. Here's an example:
You can consider “learning all kanji” in Japanese as the equivalent to “learning all morphemes” in English.
You commonly study the etymology of words you come to know of, not the other way around.
Likewise, you should probably consider studying the kanji of words you come to know of, and not the other way around.
So when you read that the average high-schooler should recognize 2136 kanji, and that some literate people can read more than 3000… don't panic.
You probably know more than 25000 English words yourself, comprising thousands of morphemes!
Bonus: Interesting side-effect: Japanese does not require explicit conversion of morphemes to sound to be able to write them. For instance, 経緯 could be pronounced いきさつ or けいい, but it's not really important that the word has two readings. It can be read and understood without needing to pick a pronunciation for it.
If you read the previous paragraph, which I encourage you to do, you already know that kanji can often be mapped to the morphemes forming the words.
Add to this that Japanese does not have many possible sounds. This has the consequence that there are many, many, many “homophones”: words that mean completely different things, but that you write the same way when using a phonetic writing method.
At first you don't know too many words, so it remains manageable.
But as your vocabulary grows, you'll experience more and more difficulty in distinguishing homophones, especially among the 漢語.
This particular category of words will make your learning a living hell if you base yourself on a phonetic writing method such as rōmaji.
As an example, しょうじょう, which you can write as shoujou or shōjō depending on your romanization scheme, can be one of the following (list not exhaustive):
Next, you need to know that in speaking, two homophones can often be distinguished by the pitch accent that Japanese has.
This means that rōmaji, unless you add pitch accent markers on it, does not actually represent spoken Japanese accurately.
Be my guest and write 帰る “↑ka↓eru” and 蛙 “ka↑eru”, but that implies you know which writing is implied behind that… why not just learn the actual writing?
Last nail in the coffin: pitch accent for various words differs depending on the province in Japan. So you'd have to specify for which province you're writing your rōmaji.
Rōmaji are a crutch; their use cases are to bootstrap learning kana, and with a ワープロ scheme for your IME.
The actual Japanese writing (including kanji), actually makes comprehension easier, not harder.
Like 125 million Japanese people, you should aim to read Japanese in the form it's normally written.
To begin with, a spaced repetition learning system will not teach you Japanese on its own.
A SRS is a tool which, like any tool, has specific use cases in which it excels.
SRS are the perfect fit for e.g.:
However, if you try to learn Japanese from vocabulary flash cards alone, you will likely find yourself short of:
Reading a book or a manga can prove more beneficial for intermediate learners, since those develop topics over entire chapters. Authors get the occasion to use a broad range of words and expressions relevant to a topic, which is a good occasion to acquire some fluency in it, and perhaps make your own flash cards, based on your discoveries.
Many have tried, but trying to cut corners simply won't get you there.
This is not an ode to discouragement, but rather a warning that you probably shouldn't take up Japanese studies if you count on being done with it any time soon.
If you enjoy studying, or rather, discovering Japanese, rejoice: you have many years of daily discoveries ahead!
To give more concrete numbers, unless talking about Daniel Tammet, it is generally observed that people who get seriously interested in Japanese material start to be able to e.g. read their manga properly in 5 years' time, give or take a few.
If you're going to ask why, here is an attempt to describe rational reasons for this:
Although some hints are sprinkled over the previous paragraph, debunking this one cannot hurt.
In Japanese, everything is linked, so you cannot decide of an order to take things in.
In some cases, the only way to tell how to read a word is to deduce that information from context, after you have understood the grammar of the sentence around it.
A good example of this is 開く, which can be read ひらく or あく depending on what sort of motion we appear to be talking about.
As a rule of thumb, it will be the former if the motion can be described as spreading, such as that of a hand or flower. The latter will apply for openings that create a gap, like sliding doors, but these can also ひらく.
It can get tricky; honing your intuition on examples will be the only way to tell in certain cases.
Trying to cut up the “problem” in arbitrary ways would only result in additional difficulty.
Experience showed that the easiest way to go about understanding Japanese is to study all aspects of the sentences you examine, one at a time.
If you approach it that way, you will make the most out of your material from the very start.
Here's bad news. Occidental textbooks (guidetojapanese.org, genki, minna no nihongo and so many others) attempt to describe Japanese with a grammar that is only a good fit for European languages.
Nice! Reusing our existing knowledge to save time?
Well, the reuse of your preexisting knowledge is really the only appeal of this overwhelmingly widespread approach.
It is so widespread in fact, that hardly anyone imagines an alternative could exist, like… using a Japanese grammar to study Japanese, maybe?
The Occidental approach kind of works at first, but puts you in a dead end. You then have to extricate yourself from it through immersion to make any further progress. Many people give up before that.
The problem is, European grammar does not fit the Japanese language well, and will leave many questions unanswered. It will also leave you clueless facing certain sentences, as it didn't provide the tools to parse them.
One such example is with the が particle, which is often portrayed as a "subject" particle. But Japanese grammar has no notion of a subject, despite Meiji period scholars wanting it to have one, to rival English: how could Japanese lack a feature English has? Preposterous!
Indeed it can indicate the actor of an action, but the main keys to cracking it are:
Okay, so textbooks are all wrong, trying to use European grammar concepts on Japanese. So what can you do?
Well, there's someone called Cure Dolly who, despite a weird voice filter (thankfully there are subtitles), gets this all straight; check these out:
Initially written 2017-08-19 - this content is in the public domain.