2018 UPDATE: Rikaichan is no longer available but you can get Rikaichamp for Firefox and Chrome. Since it is almost identical to Rikaichan, this article is still relevant.
People seem to think of Rikaichan as “that kanji-recognizing thing”. It is that of course. But it is far more. It is not only a free Japanese dictionary, but it is what every Japanese Dictionary should be and isn’t. It is a reading-writing tool of unparalleled power and it is going to be the number one utility in your Japanese toolkit.
Why? Let me explain a little. In any foreign language you have probably tried looking up a word you find only to discover it isn’t in your dictionary. If you ask why, you are told “Oh, that’s in the passive plenipotentiary case. You have to look it up in dictionary form.”
To which you reply “but it’s a squeaking word isn’t it? People use it. I didn’t even recognize what case it was in. Why can’t I just look it up?”
Well, because your dictionary is a foot thick already. If it contained every possible case and inflection of every word it would be ten volumes. And that is what’s wrong with paper dictionaries.
Rikaichan will recognize a word whatever case it is in and tell you the case. Even if the kanji wasn’t used. Here is an example. We are worrying about the fate of a certain walking, talking mushroom:
What is that word “ubawareta”? If we hover Rikaichan over it, we find out. The word in dictionary form is actually 奪う ubau, to snatch away or steal. However this is in the passive, past form, as Rikaichan also kindly informs us.
So the sentence means “Has she been snatched away by evil birds?” (I love the passive form for all the reasons Western critics hate it – but that is a whole ‘nother article).
Rikaichan also tells us that the word is transitive (vt), that it is a godan verb ending in u (v5u) and that it is a common, or popular word (P). All of these can be important pieces of information on some occasions. The P for example helps answer the question “Is this an obscure word or one I should be trying to learn?”
Now this is not just a reading tool but a writing tool. You can check your own attempts at conjugation on the fly. If you can’t remember if a ru-ending verb is ichidan or godan, just type it, hover Rikaichan, and you have the answer. Similarly it will tell you what kind of adjective a word is, whether a verb is transitive or intransitive and various other things. As you start incorporating it into your routine you will find that Rikaichan answers a good half of your grammatical questions instantly and on the fly. It will even recognize some common phrases and turns of speech.
But there is another important aspect to Rikaichan. The toolbar. The important point about this is the search box (on Mac you can add the Rikaichan search box to Firefox’s navigation bar so you don’t need the clutter of the whole toolbar – I am not sure if this works on Windows machines too). This is important because it analyzes kanji into their component parts for you. Here is an example. I entered the word 正解 seikai (correct answer or solution) into my Rikaichan search box:
You can click for a bigger view. As you see, you get the readings of the kanji plus a breakdown of their components. And as you see, I have the search-box alone installed beside the address bar of my browser, ready to analyze kanji at all times. The yellow box (I have it yellow as I find it less obtrusive) just pops up over whatever else is on screen. You just click to get rid of it.
I won’t comment too much on the importance of this right now because we talk about learning vocabulary/kanji in various other places. But as you take a logical, meaningful approach to Japanese vocabulary and how it fits together, I promise you, you are going to find this invaluable.
If you are serious about Japanese, Rikaichan is reason enough to choose Firefox browser. It is reason enough to use web-based word-processor so you can check your writing as you go. It is also a good reason to switch to the Thunderbird mail app if you use a mail app. Thunderbird also supports Rikaichan so you can use it to help you read and write your Japanese mail. You can also use the toolbar (or just the search box) to analyze kanji from within your mail app.
We will be talking more about the logic of learning Japanese and how beautifully it all fits together. You will find that Rikaichan makes all of this much easier and more immediately accessible.