Dakuten (濁点), colloquially ten-ten ("dot dot"), is a diacritic sign most often used in the Japanese kana syllabaries to indicate that the consonant of a syllable should be pronounced voiced. Handakuten (半濁点), colloquially maru ("circle"), is a diacritic used with the kana for syllables starting with h to indicate that they should instead be pronounced with [p].

Glyphs

The dakuten resembles a quotation mark, while the handakuten is a small circle, both placed at the top right corner of a kana character:

□゛ dakuten (゛)

□゜ handakuten (゜)

The glyphs are identical in the hiragana and katakana scripts. The combining characters are rarely used, as Unicode and all common Japanese encodings provide precomposed glyphs for all possible dakuten and handakuten character combinations in the standard hiragana and katakana ranges.

Due to the similarity of dakuten and quotation marks ("), written Japanese often uses square quotes (「」) instead.

Phonetic shifts

The following table summarizes the phonetic shifts caused by the dakuten and handakuten. Literally, syllables with dakuten are "muddy sounds" (濁音 dakuon), while those without are "clear sounds" (清音 seion), but the handakuten (lit. "half-muddy mark") does not follow this pattern.

See hiragana for a complete table.

Kana iteration marks

The dakuten can also be added to hiragana and katakana iteration marks, indicating that the previous kana is repeated with voicing:

Both signs are relatively rare, but can occasionally be found in personal names such as Misuzu (みすゞ). In these cases the pronunciation is identical to writing the kana out in full.

The V sound

In katakana only, the dakuten may also be added to the character ウ u and a small vowel character to create a /v/ sound, as in ヴァ va. As "V" does not exist in Japanese, this usage applies only to some modern loanwords and remains relatively uncommon, and e.g. Venus is typically transliterated as ビーナス biinasu instead of ヴィーナス viinasu. Many Japanese, however, would pronounce both the same, with a /b/ sound, and may or may not recognize them as representing the same word.

An even less common method is to add dakuten to the w- series, reviving the now defunct characters for /wi/ (ヰ) and /we/ (ヱ). /vu/ is represented by using /u/, as above; /wo/ becomes /vo/ despite its W normally being silent. Precomposed characters exist for this method as well (/va/ ヷ /vi/ ヸ /vu/ ヴ /ve/ ヹ /vo/ ヺ), although most IMEs do not have a convenient way to enter them.