Pronunciation I: Vowels
日本語の音韻体系①・母音
In Lesson 1, we will explore the vowels in Japanese—sounds like “ah” and “eh.” This lesson will show how Japanese vowels are pronounced differently from their English counterparts, helping you develop an accurate foundation in pronunciation.
The Five Vowels of Japanese
日本語の母音・5つの音
While American English has 14 distinct vowel sounds, Standard Japanese only has five distinct vowel sounds: /a/ (ah), /i/ (ee), /u/ (oo), /e/ (eh) and /o/ (oh). The approximations in parentheses are meant to serve as a general guide.
| /a/ | Katana (sword) | Sakana (fish) | Aka (red) | Atama (head) |
| /i/ | Ichi (one) | Ni (two) | Imi (meaning) | Shichi (seven) |
| /u/ | Kutsu (shoes) | Mizu (water) | Tsuki (moon) | Umi (sea) |
| /e/ | Seki (seat) | Mise (store) | Pen (pen) | Tegami (letter) |
| /o/ | Otoko (man) | Okane (money) | Koko (here) | Ocha (tea) |
When either at the start or end of a phrase, Japanese vowels are typically accompanied with a glottal stop (声門閉鎖音). This sound can be heard at the start and end of the phrase “uh-oh.”
The Japanese /a/ 日本語の「ア」
The Japanese /a/ vowel is made with the tongue positioned closer to the center of the mouth compared to the American English “ah” vowel. To approximate this sound, try saying the English word “I,” but stop before enunciating the final “ee” sound at the end.
| Aa (ah!; oh!) | Asa (morning/hemp) | Ana (hole) |
| Taka (hawk) | Karada (body) | Mata (again) |
| Yama (mountain) | Hana (flower/nose) | Tana (shelf) |
The Japanese /i/ 日本語の「イ」
The Japanese /i/ always sounds like “ee.”
| Higashi (east) | Nishi (west) | Hashi (chopsticks) |
| Kita (north) | Minami (south) | Kani (crab) |
| Ima (now) | Ki (tree) | Itachi (weasel) |
The Japanese /u/ 日本語の「ウ」
Of the five vowels, the Japanese /u/1 is the most peculiar because it is unrounded. While the sides of the lips are compressed, the lips remain unrounded and do not protrude as they do with the English /u/ sound.
| Kuni (country) | Niku (meat) | Yūbe (evening) |
| Tsunami (tsunami) | Inu (dog) | Basu (bus) |
| Natsu (summer) | Fuyu (winter) | Haru (spring) |
Although the unrounded /u/ is a uniquely Japanese sound, many dialects utilize a rounded /u/ similar to that in English. As a result, many native instructors from regions outside East Japan (including Tokyo) may not use the unrounded pronunciation.
The Japanese /e/ 日本語の「エ」
The Japanese /e/ is produced with the tongue positioned midway in the mouth and with unrounded lips. Although it resembles the English /e/ sound, the Japanese /e/ remains a pure vowel rather than a diphthong2. Additionally, the tongue is not placed as close to the roof of the mouth as it is in English.
| Megane (glasses) | Eki (liquid/train station) | Kaze (wind/a cold) |
| Me (eyes) | Erebētā (elevator) | Sekai (world) |
| Kame (turtle) | Same (shark) | Kesa (this morning) |
The Japanese /o/ 日本語の「オ」
The difference between /e/ and /o/ lies in tongue placement. For /e/, the tongue is positioned forward in the mouth. For /o/, the tongue is positioned in the back of the mouth.
In Japanese, short vowels are pronounced quickly and without exaggeration. However, if a vowel is long, its pronunciation time is doubled. This difference, especially between short /o/ and long /ō/, can be challenging for English speakers to detect. Extra care is needed to ensure that vowels are pronounced with the correct length.
| Ho(h)o (cheek(s)) | Sora (sky) | Tori (bird) |
| Yoru (night) | Koe (voice) | Kotoba (word) |
| Mono (thing) | Kōri (ice) | Oto (sound) |
| Soko (bottom/there) | Tokoro (place) | Tōri (street) |
Short Vowels vs Long Vowels
長短母音の区別
Japanese distinguishes between short vowels and long vowels. Short vowels count as one mora, while long vowels, indicated by macrons (e.g., ō), count as two morae. To help visualize this, think of each mora as a single clap, where each clap is equal in length, regardless of speaking speed.
Adjacent vowels, whether they are the same or different sounds, are pronounced as separate morae3. Syllables are language-specific units of organization for sequences of sounds. When “syllables” are equal in length in relation to one another, they are more accurately described as morae. In addition to adjacent vowels being separate morae, the uvular consonant /ɴ/4 also counts as a separate mora.
| Short | Example | Morae | Long | Example | Morae |
| /a/ | Obasan (aunt) | 4 | /aa/ | Obāsan (grandma) | 5 |
| /i/ | Ie (house) | 2 | /ii/ | Īe (no) | 3 |
| /u/ | Yuki (snow) | 2 | /uu/ | Yūki (courage) | 3 |
| /e/ | E (painting) | 1 | /ee/ | Ē (yes) | 2 |
| /o/ | To (door) | 1 | /oo/ | Tō (ten things) | 2 |
[ē] vs. [e.i]
「エー」と「エイ」の区別
Many instances of [e.i] end up being pronounced as [ē]. Though pronouncing the vowels separately as [e.i]5 is always “proper,” simplifying to [ē] is commonplace6 provided that the vowels do not cross a word boundary and that the word is of Sino-Japanese7 origin.
| Spelling | Meaning | Pronunciation(s) | Word Source |
| Onēsan | Older Sister | [onēsaN] | Native |
| Tokei | Clock/watch | [tokē] or [toke.i] | Sino-Japanese |
| Ei | Stingray | [e.i] | Native |
| Hei | Wall/fence | [he.i] | Native |
| Kēki | Cake | [kēki] | Loanword |
| Tēburu | Table | [tēburu] | Loanword |
| Eigo | English | [ēgo] or [e.igo] | Sino-Japanese |
| Gakusei | Student | [gakusē] or [gakuse.i] | Sino-Japanese |
| Kirei | Pretty | [kirē] or [kire.i] | Sino-Japanese |
| Sensei | Teacher | [seNsē] or [seNse.i] | Sino-Japanese |
| Yūmei | Famous | [yūmē] or [yūme.i] | Sino-Japanese |
| Mētoru | Meter | [mētoru] | Loanword |
| Eiga | Movie | [ēiga] or [e.iga] | Sino-Japanese |
[ō] vs [o.u]
「オー」と「オウ」の区別
In Sino-Japanese words, the vowel combination [o.u] becomes [ō], provided that the vowels do not cross a morpheme8 boundary. Despite this pronunciation, [ō] in Sino-Japanese words is still written as “ou” in Japanese script.
In most native words and loanwords, [ō] is spelled regularly as “oo,” and likewise, [o.u] is spelled regularly as “ou.” Exceptions to these norms are in bold below.
| Spelling | Meaning | Pronunciation | Word Source |
| Ookii | Big | [ōkī] | Native |
| Fooku | Fork | [fōku] | Loanword |
| Koorogi | Cricket | [kōrogi] | Native |
| Kouen | Park | [kōeɴ] | Sino-Japanese |
| Tanjoubi | Birthday | [taɴjōbi] | Sino-Japanese |
| Ginkou | Bank | [giɴkō] | Sino-Japanese |
| Satou | Sugar | [satō] | Sino-Japanese |
| Reizouko | Refrigerator | [rēzōko] or [re.izōko] | Sino-Japanese |
| Koucha | Black tea | [kōcha] | Sino-Japanese |
| Soosu | Sauce | [sōsu] | Loanword |
| Omou | To think | [omo.u] | Native |
| Ou | To chase | [o.u] | Native |
| Ou | King | [ō] | Sino-Japanese |
| Tou | To question | [to.u] or [tō] | Native |
| Mou | Already | [mō] | Native |
| Kyou | Today | [kyō] | Native |
| Kinou | Yesterday | [kinō] | Native |
| Douzo | By all means | [dōzo] | Native |
| Otousan | Father | [otōsaɴ] | Native |
Most instances of [ō] in native words are spelled as “oo.” Likewise, most instances of [o.u] are spelled as “ou,” as is evident from the verbs omou (to think) and ou (to chase) listed above. However, instances of [ō] being irregularly spelled as “ou” still exist in native vocabulary, especially in adverbs. Words like “otousan” (father) for [otōsaɴ] are also particularly irregular.
The alternative pronunciation [tō] for “tou” (to question) reflects an older pronunciation norm in which instances of [o.u], even at the end of verbs, were pronounced as [ō].
[o.u] Across a Morpheme Boundary
Whenever /o/ and /u/ are adjacent to each other but separated by a morpheme boundary, [o.u] > [ō] does not occur. As a result, even if two words have identical phonetic spellings, their pronunciation can differ due to the presence of a morpheme boundary.
| Spelling | Meaning | Pronunciation | Breakdown |
| Koushi | Calf | [ko.ushi] | Composed of ko- (small) and ushi (cow) |
| Koushi | Lecturer | [kōshi] | Kou (Chinese root meaning “lecture”) and shi (Chinese root meaning “expert”) |
“IU” = “Yū” 「イウ」＝「ユー」
The most irregular spelling regarding vowel pronunciation is the word iu (to say), as it is pronounced as [yū].
- The proper notation for this vowel in the International Phonetic Alphabet (IPA), is ɯ or ɯ̟ᵝ more specifically. The IPA is used to transcribe sounds for all the world’s languages. ↩︎
- A diphthong is a sound formed by the combination of two vowels in a single syllable. ↩︎
- English speakers are prone to pronouncing adjacent vowel sounds as diphthongs. Japanese does not allow for diphthongs and imposes that adjacent vowels be pronounced as distinct morae. ↩︎
- The pronunciation of /N/ is complicated. For now, recognizing it as a separate mora that always follows a vowel is all you need to know. ↩︎
- Placing a dot in between adjacent vowels helps with recognizing them as separate morae. ↩︎
- The simplification of /ei/ to [ē] is a feature of East Japanese dialects. It is viewed as the prestigious pronunciation in Standard Japanese for words in which this sound change occurs. ↩︎
- Sino-Japanese words are derived from roots borrowed from Chinese over centuries of contact since antiquity. They often exhibit unique phonological features not present in native vocabulary. ↩︎
- “Morpheme” means “unit of meaning.” ↩︎