Language input keys, which are usually found on Japanese and Korean keyboards, are keys designed to translate letters using an input method editor. On non-Japanese or Korean keyboard layouts using an IME, these functions can usually be reproduced via hotkeys, though not always directly corresponding to the behavior of these keys.
Keys for Japanese Keyboards
The OADG 109A and older 109 keyboard layouts which are the standard for Microsoft Windows have five dedicated language input keys:
halfwidth/fullwidth/kanji at the top left key of the keyboard;
alphanumeric, combined with non-language specific key ;
katakana/hiragana/rōmaji, on the right of the space bar, next to.
Apple keyboards designed for Mac OS X have two language input keys: alphanumeric and kana. The keyboards for NEC PC-9800 series, which was dominant in Japan during the 1980s and early 1990s, have three language input keys: kana, NFER, XFER. For non-Japanese keyboards, the following shortcuts can be used for typing Japanese on English keyboard with Windows:
switch between languages
switch to Hiragana
if in alphanumeric mode change to Hiragana, then switch to Katakana
switch between full-width Hiragana ↔ full-width alphanumeric
switch between kana ↔ half-width alphanumeric
toggle kana/direct input
no conversion, all previous characters are accepted "as is"
convert current word to the first word in the list of proposals
convert to the 2-6th word in the list
convert selected word/characters to full-width hiragana : ホワイト → ほわいと
Half-width/Full-width/Kanji toggles between entering half-width or full-width characters, and also between IME on and off. Prior Windows 98 and older systems, the key was only with Half-width/Full-width function.
Kanji
Used to switch between entering Japanese and English text. It is not found as a separate key in the modern Japanese 106/109-key keyboard layout. On the Common Building Block Keyboard for Notebooks, as many 106/109-key keyboards, the Kanji key is located on the Half-width/Full-width key, and needs the key. It is found as a separate key on the IBM PS/55 5576-001 keyboard. On the IBM PS/55 5576-002 keyboard, it is mapped to the left Alt key.
Alphanumeric
Alphanumeric toggles alphanumeric characters. In the Japanese 106/109-key layout, it is located on the Caps Lock key. Pressing Alphanumeric/Caps Lock key alone actually means alphanumeric function, a user has to press key to get caps lock function.
Conversion
Conversion is used to convert kana to kanji. In the Microsoft IME, Conversion selects conversion candidates on highlighted input, and is used to display the previous candidate, or zenkōho. The alt version of this key is also pronounced zenkōho, which means "all candidates", shows all input candidates.
Non-conversion
Non-conversion specifies that the kana characters entered are not to be converted into kanji candidates.
Katakana/Hiragana/Rōmaji
Katakana,hiragana,rōmaji used to switch between hiragana or katakana characters. It can also be found for switching between hiragana, katakana and rōmaji as shown below. or toggles between rōmaji input and direct kana input in some IMEs.
On the top of the key, the backslash is replaced with the or both of them are printed. The backslash has the shape of the Won sign including system fonts such Gulim and Malgun Gothic. Note that vertical bar is also replaced as the broken bar on some South Korean keyboards, but the broken bar in Unicode is not inputted by most of Korean IMEs.
Keyboards with a small key and large "backwards-L" shaped key are commonly used in South Korea.
There are two additional keys: Han/Yeong and Hanja keys. They do not exist as independent keys on some keyboards.
Han/Yeong (한/영)
It toggles between entering Korean and English. Many computer systems support alternative keys or key sequences for keyboards without the Han/Yeong key. It is absent from the keyboards of most portable computers in South Korea, where the right key is used instead. On the right key of these devices, only "한/영" or both "한/영" and Alt are printed.
Hanja (한자)
It converts Hangul to Chinese characters or some special characters. Many computer systems support alternative keys or key sequences for keyboards without the Hanja key. It is absent from the keyboards of most portable computers in South Korea, where the right key is used instead. On the right key of these devices, only "한자" or both "한자" and Ctrl are printed.