First opened Saturday, October 1, 2005
十
じゅう
- head-high (atamadaka): falls after mora 1
How to read it: a line over a kana means the voice is high there, and ↓ marks where it drops. A kana with no line is low. With no ↓ the pitch stays high to the end and does not drop even on a following particle (が, は).
ten
Jū, “ten”, is from Middle Chinese 十 (MC dzyip), with a literary Hokkien cousin, si̍p.
Taken apart
No breakdown is shown for this word: Wiktionary's text for it doesn't give a split that spells the word and joins to its reading, and any other split would be a guess.
Written with 十
In a sentence
もう夜の十時だ。
It's already ten o'clock at night.
十時半の電車に乗ります。
I'm going to take the 10:30 train.
Sentences are from Tatoeba (CC BY 2.0 FR), picked by fixed rules from a dated export and shown unchanged. Nobody has reviewed them one by one.
What Wiktionary says
Quoted line by line from Wiktionary's Etymology section for this reading, taken from one dated dump so it can't change underneath us. Nothing below is paraphrased.
- “/ʑipʉ/ → /ʑiɸu/ → /ʑɨu/ → /ʑuː//ʑiʔ/ → /ʑi~̚/”
- “From Middle Chinese 十 (MC dzyip). Compare literary Hokkien 十 (si̍p).”
Source: Wiktionary: 十 (dump of 2026-09-02), available under CC BY-SA 4.0. Reading, meaning and part of speech from JMdict, and kanji readings from KANJIDIC2 (EDRDG).
Other readings of 十 on the same Wiktionary page
These describe other words written the same way, not じゅう. They are quoted for context: the parts, layer and processes of this word are not taken from them.
とお
- “⟨to₂wo⟩ → */təwo/ → /towo/ → /toː/”
- “From Old Japanese, ultimately from Proto-Japonic *təwə. The initial to- may be related to the -tu in 五 (itu, “five”), following similar vowel alternations as seen in the numerals for 1-4 and their doubles. Alternatively this word may be related to 撓む (towomu→tōmu, “to bend”), 撓寄る (towoyoru, “to flex”), 撓 (towowo, “bent”), from the way ones fingers bend when counting using them. See the Proto-Japonic reconstruction page for more theories.”
と
- “Shift from tō above.”
そ
- “⟨so₁⟩ → */sʷo/ → /so/”
- “From Old Japanese.”
- “Used in compounds.”
しい
- “From Mandarin 十 (shí).”
What the labels mean
- 漢語 Sino-Japanese
- Words built from Chinese-derived morphemes — borrowed from Chinese or coined in Japan out of Chinese parts — read with on'yomi.
- Borrowing
- Taken over from another language.
- Sound change
- The pronunciation shifted over the centuries.