IPA symbols for English vowels

The IPA vowel symbols are typically more difficult than consonants for speakers of English to learn, since they seldom represent the sounds that the corresponding English letters (usually) do. The major vowel symbols, [a], [e], [i], [o], and [u], represent the sounds that the corresponding letters do in the spelling systems of many European languages, such as Spanish and Italian or, to a lesser extent, French or German. (The symbols also correspond fairly closely to the way the letters were originally used in English orthography. But five hundred years ago in a major historical change, the Great English Vowel Shift, English speakers changed the way they pronounced many words without at the same time changing their conventional spelling.)

In order to represent all the vowels of English, we need more symbols than the five vowel letters of the Roman alphabet. The conventional names for these symbols are:
[ɪ]small capital I
[ɛ]epsilon [ˈɛpsəˌlɑn]-- a Greek letter
[ʊ]sometimes called upsilon [ˈʌpsəˌlɑn]
[æ]digraph a-e -- usually just "digraph" [ˈdajˌɡɹæf]
[ɑ]script A
[ɔ]open O
[ʌ]caret [ˈkɛɹət]

The vowels

[i] [məˈʃin]machine
[hid]heed
[bit]beet, beat
[snik]sneak
[ɪ] [bɪt]bit
[mɪs]miss
[hɪd]hid
[e] [pæˈse]passé
[bet]bait
[hed]hayed
[mek]make
[stek]steak
[ɛ] [hɛd]head
[bɛt]bet
[mɛni]many %
[æ] [hæd]had
[bæt]bat
[ɑ] [ˈfɑðɹ̩]father
[bɑt]bought %
[kɑt]cot, caught %
[lɑ]law %
[o] [hod]hoed
[bot]boat
[lo]low
[bo]beau
[ʊ] [pʊt]put
[hʊd]hood
[bʊk]book
[u] [blu]blue
[hud]who'd
[but]boot
[dɹu]drew
[ʌ] [bʌt]but
[kʌp]cup
[ˈdʌbl̩]double
[aj] [aj]I, eye
[flaj]fly
[bajt]bite
[hajd]hide
[najt]night
[aw] [kaw]cow
[bawt]bout
[hawd]how'd
[ɔj] [tɔj]toy
[bɔjd]Boyd
[nojz]noise
[ə] [bəˈnænə]banana
[əˈnʌf]enough
[ˌmænəˈtobə]Manitoba
[ɹ̩] [bɹ̩d]bird
[fɹ̩]fur, fir
[hɹ̩d]heard, herd

Syllabic [ɹ̩]

There is a major split between English dialects where the pronunciation of the word bird contains an [ɹ] sound (e.g., western Canada, central and western U.S., northern England) and those where it does not (e.g., southern England, Australian, parts of the north-east and southern U.S.). In dialects which do not use an r sound in bird, the vowel between the [b] and the [d] is traditionally transcribed as [ə] or [ɜ].

Dialects which do use an [ɹ] sound in bird tend to use nothing but. In normal western Canadian or American speech, the period of time between the [b] and the [d] will be entirely occupied by an [ɹ] sound, and there will be no other vowel in the word. The [ɹ] is acting as the core of the syllable in [bɹd], a privilege which is usually reserved for vowels. A vertical line diacritic is used to mark those occasions where [ɹ] has a special vowel-like role in a syllable. The usual transcription bird is therefore [bɹ̩d]. (Sometimes you'll run across the symbols [ɚ] or [ɝ] or even the sequence [əɹ] used instead of [ɹ̩].)

Open O

Many dialects of English have another vowel, which is represented by the "open o" symbol, [ɔ].

Most dialects spoken in Canada and in the central and western U.S. pronounce the following pairs of words identically:
cot [kɑt]caught [kɑt]
pa's [pɑz]pause [pɑz]
Don [dɑn]Dawn [dɑn]
Other dialects, including British Received Pronunciation and many in the north-eastern and southern U.S., pronounce the words with different vowels:
cot [kɑt]caught [kɔt]
pa's [pɑz]pause [pɔz]
Don [dɑn]Dawn [dɔn]

Historically, all dialects had the contrast between [ɑ] and [ɔ]. The ones which now pronounce cot and caught identically have lost the contrast over the generations, merging both into [ɑ]. Most speakers who pronounce caught as [kɑt] still use a vowel very close to [ɔ] as the starting point of the diphthong [ɔj] and often also before [ɹ], as in four [fɔɹ].