Editing Katakana (section)

=== Overview ===
{| align=right border="0" cellpadding="0" style="width: 14em; margin-left: 1em; margin-bottom:1em"
|-
|
{| class="wikitable" 
|+ Gojūon – Katakana characters with a nucleus
!
! ''a'' !! ''i'' !! ''u'' !! ''e'' !! ''o''
|- align=center
!title="no onset"|{{color|gray|∅}}
|<big>[[A (kana)|ア]]</big>||<big>[[I (kana)|イ]]</big>||<big>[[U (kana)|ウ]]</big>||<big>[[E (kana)|エ]]</big>||<big>[[O (kana)|オ]]</big>
|- align=center
!''k''
|<big>[[Ka (kana)|カ]]</big>||<big>[[Ki (kana)|キ]]</big>||<big>[[Ku (kana)|ク]]</big>||<big>[[Ke (kana)|ケ]]</big>||<big>[[Ko (kana)|コ]]</big>
|- align=center
!''s''
|<big>[[Sa (kana)|サ]]</big>||<big>[[Shi (kana)|シ]]</big>||<big>[[Su (kana)|ス]]</big>||<big>[[Se (kana)|セ]]</big>||<big>[[So (kana)|ソ]]</big>
|- align=center
!''t''
|<big>[[Ta (kana)|タ]]</big>||<big>[[Chi (kana)|チ]]</big>||<big>[[Tsu (kana)|ツ]]</big>||<big>[[Te (kana)|テ]]</big>||<big>[[To (kana)|ト]]</big>
|- align=center
!''n''
|<big>[[Na (kana)|ナ]]</big>||<big>[[Ni (kana)|ニ]]</big>||<big>[[Nu (kana)|ヌ]]</big>||<big>[[Ne (kana)|ネ]]</big>||<big>[[No (kana)|ノ]]</big>
|- align=center
!''h''
|<big>[[Ha (kana)|ハ]]</big>||<big>[[Hi (kana)|ヒ]]</big>||<big>[[Fu (kana)|フ]]</big>||<big>[[He (kana)|ヘ]]</big>||<big>[[Ho (kana)|ホ]]</big>
|- align=center
!''m''
|<big>[[Ma (kana)|マ]]</big>||<big>[[Mi (kana)|ミ]]</big>||<big>[[Mu (kana)|ム]]</big>||<big>[[Me (kana)|メ]]</big>||<big>[[Mo (kana)|モ]]</big>
|- align=center
!''y''
|<big>[[Ya (kana)|ヤ]]</big>|| <ref name=":0">See [[#Obsolete kana|obsolete kana]]</ref> ||<big>[[Yu (kana)|ユ]]</big>|| <ref name=":0"/> ||<big>[[Yo (kana)|ヨ]]</big>
|- align=center
!''r''
|<big>[[Ra (kana)|ラ]]</big>|||<big>[[Ri (kana)|リ]]</big>||<big>[[Ru (kana)|ル]]</big>||<big>[[Re (kana)|レ]]</big>||<big>[[Ro (kana)|ロ]]</big>
|- align=center
!''w''
|<big>[[Wa (kana)|ワ]]</big>||<big>[[Wi (kana)|ヰ]]</big>|| <ref name=":0"/> ||<big>[[We (kana)|ヱ]]</big>||<big>[[Wo (kana)|ヲ]]</big>
|- align=center
| colspan="6" | <big>[[ン]]</big> '''(''n'')'''
|}
|}
The complete katakana script consists of 48 characters, not counting functional and diacritic marks:
* 5 ''[[syllable nucleus|nucleus]]'' vowels 
* 42 [[syllable core|''core'' or ''body'']] ([[syllable onset|onset]]-nucleus) syllabograms, consisting of nine consonants in combination with each of the five vowels, of which three possible combinations (''yi'', ''ye'', ''wu'') are not canonical
* 1 ''[[syllable coda|coda]]'' consonant

These are conceived as a 5×10 grid ({{Lang|ja-latn|gojūon}}, 五十音, literally "fifty sounds"), as shown in the adjacent table, read {{nowrap|ア (''a'')}}, {{nowrap|イ (''i'')}}, {{nowrap|ウ (''u'')}}, {{nowrap|エ (''e'')}}, {{nowrap|オ (''o'')}}, {{nowrap|カ (''ka'')}}, {{nowrap|キ (''ki'')}}, {{nowrap|ク (''ku'')}}, {{nowrap|ケ (''ke'')}}, {{nowrap|コ (''ko'')}} and so on. The {{Lang|ja-latn|gojūon}} inherits its vowel and consonant order from [[Sanskrit]] practice. In [[Horizontal and vertical writing in East Asian scripts|vertical text]] contexts, which used to be the default case, the grid is usually presented as 10 columns by 5 rows, with vowels on the right hand side and ア (''a'') on top. Katakana [[glyph]]s in the same row or column do not share common graphic characteristics. Three of the [[syllabogram]]s to be expected, ''yi'', ''ye'' and ''wu'', may have been used idiosyncratically with varying [[glyph]]s, but never became conventional in any language and are not present at all in modern Japanese.

The 50-sound table is often amended with an extra character, the nasal ン (''n''). This can appear in several positions, most often next to the ''N'' signs or, because it developed from one of many ''mu'' [[hentaigana]], below the ''u'' column. It may also be appended to the vowel row or the ''a'' column. Here, it is shown in a table of its own.

The script includes two diacritic marks placed at the upper right of the base character that change the initial sound of a syllabogram. A double dot, called ''[[dakuten]]'', indicates a primary alteration; most often it voices the consonant: ''k''→''g'', ''s''→''z'', ''t''→''d'' and ''h''→''b''; for example, {{nowrap|カ (''ka'')}} becomes {{nowrap|ガ (''ga'')}}. Secondary alteration, where possible, is shown by a circular ''[[handakuten]]'': ''h''→''p''; For example; {{nowrap|ハ (''ha'')}} becomes {{nowrap|パ (''pa'')}}. Diacritics, though used for over a thousand years, only became mandatory in the Japanese writing system in the second half of the 20th century. Their application is strictly limited in proper writing systems,{{clarify|reason = 'Strictly limited' in what sense? 'Proper' in what sense? |date=September 2016}} but may be more extensive in academic transcriptions.

Furthermore, some characters may have special semantics when used in smaller sizes after a normal one (see below), but this does not make the script truly [[Bicameral script|bicameral]].

The layout of the {{Lang|ja-latn|gojūon}} table promotes a systematic view of kana syllabograms as being always pronounced with the same single consonant followed by a vowel, but this is not exactly the case (and never has been). Existing schemes for the [[romanization of Japanese]] either are based on the systematic nature of the script, e.g. [[nihon-shiki]] チ ''ti'', or they apply some Western [[graphotactics]], usually the English one, to the common Japanese pronunciation of the kana signs, e.g. [[Hepburn-shiki]] チ ''chi''. Both approaches conceal the fact, though, that many consonant-based katakana signs, especially those canonically ending in ''u'', can be used in coda position, too, where the vowel is [[unvoiced]] and therefore barely perceptible.