About the English to katakana converter

This is an experimental converter to change English into katakana. The English pronunciations are taken from the CUVPlus dictionary. (This contains only British English pronunciations and spellings.) The rules used by the converter are the rules described in the FAQ page on writing an English word in Japanese. Type in a word and you will see the pronunciation of the word in International Phonetic Alphabet (IPA) plus two varieties of conversion into katakana.

Spelling-based conversion

Japanese uses some spelling-based and non-pronunciation based conversion rules for the following cases:
  1. A schwa vowel (ə in IPA) in the middle of a word is converted into a Japanese vowel based on the word's spelling.
  2. A schwa vowel ə at the end of the word, such as the vowel at the end of "doctor", is usually converted into a Japanese long "aa" vowel regardless of the spelling. Similarly, a short I vowel is usually made into a Japanese long "ii" vowel.
  3. The vowel in "front", "monkey" (ʌ in IPA), etc. spelt with an "o" is converted into a Japanese "o" vowel rather than a Japanese "a" vowel.
The converter offers two transliterations, one based on pronunciation plus the above spelling rules, and one based solely on the pronunciation. For example:
English word Pronunciation (IPA) Pronunciation and spelling conversion Pronunciation-only conversion
gunmen 'gʌnmən ガンメン ガンムン
monkey 'mʌŋkɪ モンキー マンキ

Known bugs

I know of the following bugs and limitations:
  1. There are some problems with handling of the sokuon for short vowels.
  2. The spelling-based conversion will break down sometimes, since the algorithm I use to break English words into syllables based on their spelling is very simplistic and fails for about 10% of the words in the dictionary.
  3. Only British spellings and pronunciations are available.
  4. The converter is extremely slow. It reads the whole dictionary into memory before starting.
  5. Sometimes the choice of the "u" vowel as a replacement for the schwa causes oddities, especially at the ends of words.
  6. The Japanese uses a long vowel "aa" for the schwa sound in Richard. I haven't worked out how to do this correctly yet.
If you have any queries or comments, please email Ben Bullock.