text: Contrastive vowel length In many varieties of English, vowels contrast with each other both in length and in quality, and descriptions differ in the relative importance given to these two features. Some descriptions of Received Pronunciation and more widely some descriptions of English phonology group all non-diphthongal vowels into the categories "long" and "short", convenient terms for grouping the many vowels of English. Daniel Jones proposed that phonetically similar pairs of long and short vowels could be grouped into single phonemes, distinguished by the presence or absence of phonological length (Chroneme). The usual long-short pairings for RP are /iː + ɪ/, /ɑː + æ/, /ɜ: + ə/, /ɔː + ɒ/, /u + ʊ/, but Jones omits /ɑː + æ/. This approach is not found in present-day descriptions of English. Vowels show allophonic variation in length and also in other features according to the context in which they occur. The terms tense (corresponding to long) and lax (corresponding to short) are alternative terms that do not directly refer to length.
  In Australian English, there is contrastive vowel length in closed syllables between long and short  and . The following are minimal pairs of length:
  Allophonic vowel length
  In most varieties of English, for instance Received Pronunciation and General American, there is allophonic variation in vowel length depending on the value of the consonant that follows it: vowels are shorter before voiceless consonants and are longer when they come before voiced consonants. Thus, the vowel in bad  is longer than the vowel in bat . Also compare neat  with need . The vowel sound in "beat" is generally pronounced for about 190 milliseconds, but the same vowel in "bead" lasts 350 milliseconds in normal speech, the voiced final consonant influencing vowel length.
  Cockney English features short and long varieties of the closing diphthong . The short  corresponds to RP  in morphologically closed syllables (see thought split), whereas the long  corresponds to the non-prevocalic sequence  (see l-vocalization). The following are minimal pairs of length: