The transcription of English to Japanese has been done since the earliest cultural contacts between English speakers and Japanese. During the Edo period, kanji were used phonetically to write English and other foreign words, but in the modern period katakana have become the principal target script. Unlike the systems for romaji, there is no standard for transcribing into katakana, and methods vary. However, generally all methods attempt to preserve the pronuciation of English, not the spelling. That is, transcription not transliteration is done.

Reasons for transcribing

The purpose of the transcription partly determines how it is done. There are reasons why one would want to transcribe an English word to Japanese: Many legal documents, such as company registrations , require that only Japanese script is used. A computer database may need entry in Japanese script for the purpose of sorting and collation. Educators want to explain the pronunciation of English words by transcribing. Loan words from English are usually written in a transcribed form. Or one may simply be interested in how one's name looks in Japanese.

Accordingly, there are different priorities for the transcriber. The educator might want to indicate many of the subtleties of English pronuciation whereas a person naming a new product might be more concerned with the ease of pronunciation for native speakers of Japanese.

Difficulties

Japanese distinguishes fewer sounds than English. For example, Japanese does not distinguish the vowel sound of "run" and "ran". Moreover the rules by which sounds can be combined in Japanese are generally more restrictive than the English rules. As a result, the pronunciation of the transcribed word can differ rather a lot from the original word in English.

If writing for a Japanese audience, it is worth checking whether there is already an accepted transcription into Japanese, and whether the meaning of the new word has changed in Japanese. The word mishin illustrates both pitfalls: not only is this an unexpected rendering of the English word "machine", but the Japanese word's meaning is strictly limited to sewing machines only. It is also worth noting that some terms which may at first glance appear to be mangled English loanwords are, in fact, loans from other languages: koppu (drinking glass) is not a version of the English "cup" but a loan of Dutch kop, and tabako is from Portuguese tabaco, not from "tobacco".

Methods for transcription

Most Japanese people do not use a system for transcription; instead they transcribe according to their perception of the English pronunciation. However the process can be formalized, as below.

1. Write the word phonetically.

The first task is the write the word to be transcribed phonetically. The phonetic transcription should reflect the careful pronunciation of the word, and avoid slurring. So "Kate" becomes "keit" and "reform" becomes "ri:fo:m" (with ":" indicating a long vowel")

2. Simplify the consonants

Some consonant sounds that do not exist in Japanese have to be changed.

• Change "l" to "r".
• Change "th" (in "thin") to "s".
• Change "th" (in "that") to "z"
• Change "si" to "shi"
• Change "tu" to "tsu"

Other changes can be made if ease of pronunciation for native speakers of Japanese is a high priority.

• The "v" sound can be changed to "b".
• The "ti" and "di" sounds can be changed to "te" and "de"
• The "tu" sound can be changed to "tsu".

4. Split consonant groups and add vowels to terminal consonants.

There are several strict constraints on Japanese syllables:

• The only consonant clusters allowed in Japanese are the doubled consonants cch, mm, nn, ss, ssh and tt. However, note that the English digraphs ch, sh, and ts are single sounds and are allowed in Japanese.
• Japanese words can only end in vowels and the sound n.

Any sounds not matching these rules must thus be padded by a vowel, which is usually u. A notable exception is t → to and its voiced version d → do, as Japanese does not have a pure tu or du sound. A final t is often doubled for emphasis (→ tto), while in some comparatively rare cases, when less emphasis is desired, tsu is used instead. Another exception is ch → chi.

Examples:

• craft → kurafuto
• robot → robotto
• baht → baatsu
• church → chaachi
• McDonald → makudonarudo

5. Break into mora

6. Transliterate

7. Match with loan words and add a space between words

Example

English: "My hovercraft is full of eels."

Step 1:

Step 2: "mai hov@kra:ft iz ful ov i:lz"

Step 3: "mai hovakra-ft iz fur ov i-rz"

Step 4: "mai hovakura-futo izu furu ovu i-ruzu"

Step 5 - Romaji: "ma.i.ho.va.ku.ra-.fu.to.i.zu.fu.ru.o.vu.i-.ru.zu"

Step 6 - Japanese: 「マイホヴァクラーフトイズフルオヴイールズ」

Step 7 - Match with loan words and add a space between words 「マイ　ホバークラフト　イズ　フル　オブ　イールズ」