单元音（monophthong）共12个：其中/ɑ:/ /ɔ:/ / ɜ:/ /i:/ /u:/为长元音；/ ʌ/ /ɒ/ /ə/ /ɪ/ /ʊ/ /e/ /æ/为短元音。长短元音有对应关系。
单元音发音时可按舌面隆起的位置分为前元音，后元音和中元音三类。发前元音时舌的最高点在口腔的前部；发后元音时，舌的最高点在口腔的后部；发中元音时舌的最高点在口腔的中部。
音单词
以英语元音为例
前元音: [i:] [ i] [ e ] [æ]
中元音: [ʌ][ə:][ə]
后元音: [ɔ] [ɔ:] [u:] [u] [a:]
[i:] sea, he, see, piece, ceiling, street, beef, these, week, meat, agree
[ɪ]sit, build, miss, myth, palace, between, if, give, busy, gym
[e] bed, desk, head, anything, many, again, special, heavy, weather, whether, friendly
[æ] bad, land, bank, stamp, pal, Canada, taxi
[a:] car, fast, class, plant, calm, aunt
[ ɔ] hot, want, wallet, wash, what
[ ɔ:] door, more, sport, ball, warm, author, court, bought, caught
[u:] who, blue, soup,
[u] look, put, woman, could，good
[ ʌ] cup, come, blood, rough
[ ə:] girl, work, serve, nurse
[ə ] cadre, ago, forget, polite, dollar, doctor, famous, Saturday。