Are these characters pronounced exactly the same, or are they just very close? I'm making an Anki plugin to search my deck for homophones/homographs/synonyms, and then display them when I'm reviewing, and I'm not sure if for homophones words that only differ by these characters should be considered the same.

Also, is を always pronounced like お, or only when its used as a particle? Are there any other characters I should consider as being pronounced the same?

They're all the same. (ず and づ are different in some dialects but in standard Japanese they are the same.)

Akalabeth Wrote:Also, is を always pronounced like お, or only when its used as a particle?

I don't think を is ever used for anything except as the particle, is it? (Well, I have a feeling that occasionally it comes up in peoples' names, which I assume is hangover from the pre-reform kana usage, but names are weird anyway :-))

Right -- and even if you see it used in some other context it's still pronounced like お (I've heard there are some dialects where it's pronounced with a w-sound, although the o vowel frequently has a w-sound when it comes after ん.)

I hear 気をつけて pronounced with a w-sound more often than not.

を is always お in Tokyo accent and 標準語, but wo is pretty common in other dialects.　http://okwave.jp/qa/q381018.html

Though now both ず vs づ and じ vs ぢ　are pronounced exactly the same, they were different sounds until the end of Muromachi period.
In the middle of the word ず was pronounced as [zu], while づ　- as [dzu]. Same difference for じ vs ぢ: じ[zi] and ぢ[dzi]. Originally they were used in different words, but since the difference in sound became negligible it caused many headaches (even to native speakers) to distinguish when to use what. Since 1986 it is decided to always use じ and ず　instead of ぢ and づ, of course with a few exceptions to this rule.
In some places (Shikoku, Kochi prefecture) the historical difference between じ/ぢ and ず/づ still exists in pronunciation, as in the words 富士[fuzi],　藤[fudzi]; 葛[kuzu], 屑[kudzu].

Thanks for the help. I'll treat them as the same character then.

Pronounce it as the same character, but pay close attention any time づ or ぢ shows up...

LazyNomad Wrote:Since 1986 it is decided to always use じ and ず　instead of ぢ and づ

Typo in the date there? I thought this was part of all the other kana reform just after WW2...

pm215 Wrote:

LazyNomad Wrote:Since 1986 it is decided to always use じ and ず　instead of ぢ and づ

Typo in the date there? I thought this was part of all the other kana reform just after WW2...

Wikipedia Wrote:Shortly after the end of World War II, however, a new rule enforced the modern kana usage, or Gendai Kanazukai. The new kanazukai unified spellings to just two kana, zi (ジ) and zu (ズ) with the exceptions of when there is rendaku (e.g. kannaduki) and when a second duplicate kana is voiced (e.g. tuduku, when an iteration mark may be used). An exception to this unification of spelling was permitted for regions that pronounced the four kana as three or four phonemes. After a 1986 update to the Gendai Kanazukai, this exception was replaced with a statement that the unified spelling were to be primarily used, while still permitting etymologically correct spellings.

Yes and no I guess..

Wow, they permitted regional spelling variation? You learn something new every day...