Japanese Input Method

Here is a introduction to Japanese Writing System and Japanese Input Method.

Japanese Writing System

Japanese writing uses the following characters:

• Japanese Phonetic alphabets, called Kana (仮名).
• Chinese characters, called Kanji (漢字).
• English alphabets, called Romaji. (Romaji literally means “Roman characters ”.)

Of the kana, there are 2 types:

Hiragana (ひらがな, 平仮名)

Hiragana looks curvy.

Katakana (カタカナ, 片仮名)

Katakana looks angular. Katakana is used for place names, company names, imported words, emphasis, etc. Purpose of Katakana is somewhat like English uppercase letters.

There are total of 48 hiragana in modern Japanese. Same total for katakana.

The Dakuten Diacritic Mark

Dakuten ゛ is a diacritic mark that often occurs for many hiragana.

When it appears on a hiragana, it means that the consonant of the syllable should be voiced.

Character Frequency in Japanese

In formal writing, such as newspaper or books, about half are kanji, and other half are hiragana.

Source, Japanese newspaper Asahi Shimbun from the year 1993 (around 56.6 million tokens). [Chikamatsu, Nobuko; Yokoyama, Shoichi; Nozaki, Hironari; Long, Eric; Fukuda, Sachio (2000). A Japanese logographic character frequency list for cognitive science research. Behavior Research Methods, Instruments, and Computers. 32 (3): 482–500.] via Wikipedia [ Japanese writing system ] [ 2018-05-09 https://en.wikipedia.org/wiki/Japanese_writing_system ]

Here is sample of Japanese writing, from Wikipedia Japanese article on keyboard:

キーボード（英: Keyboard）は、コンピュータへの入力機器の一つであり、手指でキーを押すことでコンピュータへ文字信号などを送信するもの。様々なソフトウェア上で文字入力を基本とした機器であるが、コンピュータ (OS) の操作全般にも用いられる。

日本語における 鍵盤はkey boardからの訳語であり両者は本来的に同一のものである。欧米においては鍵盤楽器のカラクリを応用した機械式タイプライターを経て、タイプライターのインタフェースを模した電子的入力機器へと連続的に発展していった歴史的経緯により一連の概念として理解されるが、タイプライターの普及が限定的に留まった日本の社会通念においては、楽器の鍵盤と入力機器のキーボードとは断絶しており個別に扱われることが多く、電子楽器のキーボードでわずかに関連性が示される程度である。

[2017-07-16 キーボード (コンピュータ)]

Those complex looking ones are kanji (Chinese characters). The cursive looking ones are hiragana, and angular ones are katakana.

In informal writing, such as online chat, less kanji is used.

To read Japanese newspaper or books, you need to know 2k kanji. See [ Jōyō kanji ] [ 2017-07-16 https://en.wikipedia.org/wiki/J%C5%8Dy%C5%8D_kanji ] (常用漢字)

In comparison, for Chinese people reading Chinese newspaper, 3500 characters are needed. [通用规范汉字表 [Table of General Standard Chinese Characters]. Ministry of Education of the People's Republic of China. 18 Jun 2013.]

See also: How to Tell the Difference Between Chinese, Japanese, Korean?

How to Type Japanese

So, writing Japanese is hard. You have:

• ~2 thousand kanji.
• ~80 hiragana. (48 plus ~30 variation with voiced sound mark.)
• ~80 katakana.
• 52 English letters (26 lowercase and 26 uppercase.)
• digits 0 to 9, and punctuation.

There are 2 major systems to input hiragana:

• Romaji input system: Type the English letters that corresponds to the hiragana reading, and it becomes a hiragana character. Each hiragana needs 2 English letters.
• Kana input system: The keyboard keys are mapped to hiragana directly. Press the key to insert that hiragana character. (some kana character needs Shift key to enter.)

To input kanji, press a “conversion” key , then it'll convert previous kana character or phrase to kanji. Because there are many homonyms, typically a selection will popup to let you pick the correct kanji.

To input katakana, either switch to a dedicated katakana mode, or, the katakana shows as a choice among kanji character choices.

To input English letters (romaji), switch to romaji mode that lets you enter the English letters as is.

That's the basics.

Most people in Japan, use romaji method to input Japanese. That is, on a normal PC keyboard with QWERTY layout, type the English letters of the kana reading, and it becomes the hiragana character, and press a key to convert the previous word to kanji or katakana (if desired).

This is a inefficient method, but requires no learning.

See also: Chinese Input Methods

Special Keys on Japanese Keyboards

Keyboards sold in Japan usually have special keys.

They are not necessary, as you can type Japanese with US keyboard. When a keyboard doesn't have these special keys, usually Space, Return, or a Ctrl combination works.

Here is the keys.

変換

Reads “henkan”, meaning “conversion”. Convert to kanji. Sometimes the key is labeled by circular arrows 🗘. If the key doesn't exist, usually Space does the same.

無変換

Reads “muhenkan”, meaning “no conversion”. If the key doesn't exist, usually Return does the same.

かな or kana

Kana mode.

ひらがな

Hiragana mode. Or Ctrl + CapsLock

カタカナ

Katakana mode.

ローマ字

Rōmaji mode.

英数

Alphanumeric mode. (if not exist, usually CapsLock does the same. For actual caps lock, press Shift + CapsLock)

半角/全角

Half-width/Full-width. Toggles the font between full-width and half-width of English letters and punctuations.

In Japanese and Chinese, each character is a square. Text are aligned vertically, forming a grid. The width of English letters are not the same as Japanese and Chinese. So, there's the idea of full-width English alphabet characters, where each character has the same width as the square, so that the text has columns aligned.

[see Unicode Full-Width Characters]

So, there's usually a key 半角/全角 or software toggle for user to chose between full-width or half-width. Half-with means using proportional font for English.

半角

half width. (use proportional font) Sometimes shown as a crescent moon icon 🌙 or ☽ or ☾

全角

Full width monospace font. Sometimes shown as a white full moon circle 🌕.

Note: Full-width English letters in Japanese text is not necessarily preferred, since English in full-width doesn't look good.

Japanese Keyboard Layouts

Japanese Keyboard Layouts