Many linguists have attempted to produce frameworks for the analysis of style in language. There is not space for us to consider this in detail, but we should note that, for foreign learners, a typical situation - regrettably, an almost inevitable one - is that they learn a style of pronunciation which could be described as careful and formal. Probably their teachers speak to them in this style, although what the learners are likely to encounter when they join in conversations with native speakers is a "rapid, casual" style. We all have the ability to vary our pronunciation to suit the different styles of speech that we use. Speaking to one's own children, for example, is a very different activity from that of speaking to adults that one does not know well. In broadcasting, there is a very big difference between formal news-reading style and the casual speech used in chat shows and game shows. Some politicians change their pronunciation to suit the context: it was often noticed that Tony Blair, when he was prime minister, would adopt an "Estuary English" style of pronunciation when he wanted to project an informal "man of the people" style, but a BBC accent when speaking on official state occasions. In the former style, it was not unusual to hear him say something like 'We've got a problem' with a glottal stop replacing the t in 'got': wiv gɒ? ə prɒbləm. I can't remember any other prime minister doing this.

Rhythm forms an important part of style: careful, deliberate speech tends to go with regular rhythm and slow speed. Casual speech, as well as being less rhythmical and faster, tends to include a lot of "fillers" - such as hesitation noises (usually written 'um' or 'er') or exaggeratedly long vowels to cover a hesitation.

It should now be clear that the pronunciation described in this course is only one of a vast number of possible varieties. The choice of a slow, careful style is made for the sake of convenience and simplicity; learners of English need to be aware of the fact that this style is far from being the only one they will meet, and teachers of English to foreigners should do their best to expose their students to other varieties.