In our hypothetical "mechanical speech" all words would be separate units placed next to each other in sequence; in real connected speech, however, we link words together in a number of ways. The most familiar case is the use of linking r; the phoneme r does not occur in syllable-final position in the BBC accent, but when the spelling of a word suggests a final r, and a word beginning with a vowel follows, the usual pronunciation is to pronounce with r. For example:

'here' hɪə           but                  'here are' hɪər  ə

'four' fɔ:             but                   'four eggs' fɔ:r  egz

BBC speakers often use r in a similar way to link words ending with a vowel, even when there is no "justification" from the spelling, as in:

'Formula A'                    fɔ:mjələr eɪ

'Australia all out'           ɒstreɪliər  ɔ:l  aʊt

'media event'                mi:diər  ɪvent

This has been called intrusive r; some English speakers and teachers still regard this as incorrect or substandard pronunciation, but it is undoubtedly widespread.

"Linking r" and "intrusive r" are special cases of juncture; we need to consider the relationship between one sound and the sounds that immediately precede and follow it. If we take the two words 'my turn' maɪ tз:n, we know that the sounds m and aɪ, t and з:, and з: and n are closely linked. The problem lies in deciding what the relationship is between aI and t; since we do not usually pause between words, there is no silence to indicate word division and to justify the space left in the transcription. But if English speakers hear maI tз:n they can usually recognize this as 'my turn' and not 'might earn'. This is where the problem of juncture becomes apparent. What is it that makes perceptible the difference between maɪ tз:n and maɪt з:n? The answer is that in one case the t is fully aspirated (initial in 'turn'), and in the other case it is not (being final in 'might'). In addition to this, the aI diphthong is shorter in 'might'. If a difference in meaning is caused by the difference between aspirated and unaspirated t, how can we avoid the conclusion that English has a phonemic contrast between aspirated and unaspirated t? The answer is that the position of a word boundary has some effect on the realization of the t phoneme; this is one of the many cases in which the occurrence of different allophones can only be properly explained by making reference to units of grammar (something which was for a long time disapproved of by many phonologists).

Many ingenious minimal pairs have been invented to show the significance of juncture, a few of which are given below:

· 'might rain' maɪt  reɪn (r voiced when initial in 'rain', aɪ shortened), vs. 'my train' maɪ treɪn (r voiceless following t in 'train', aɪ longer)

· 'all that I'm after today' ɔ:l  ðət  aɪm  ɑ:ftə  tədeɪ (t relatively unaspirated when final in 'that')

· 'all the time after today' ɔ:l  ðə  taɪm  ɑ:ftə  tədeɪ (t aspirated when initial in 'time')

· 'tray lending' treI lendIN ("clear l" initial in 'lending') 'trail ending' treɪI endɪŋ ("dark l" final in 'trail')

· 'keep sticking' ki:p stɪkɪŋ (t unaspirated after s) 'keeps ticking' ki:ps tɪkɪŋ (t aspirated in 'ticking')

The context in which the words occur almost always makes it clear where the boundary comes, and the juncture information is then redundant.

It should by now be clear that there is a great deal of difference between the way words are pronounced in isolation and their pronunciation in the context of connected speech.