(…) There are different types of transcriptions for American English (and for British English). All of this is confusing because I am not absolutely sure whether they describe one and the same pronunciation or they describe different pronunciations.
For instance, the word “air” in American dictionaries is transcribed in many ways:
/ɛər/(this transcription is clear: it means that there is a schwa sound and the “r” sound is pronounced)
/ɛr/(this transcription is not very clear to me: is the pronunciation the same as the transcription above or does it mean that the schwa sound is omitted/deleted/?)
I have noticed that a lot of American dictionaries use the
/ɛr/transcription. Do they mean that the schwa sound is omitted or does it mean that
/ɛr/is the same as
Also, in different dictionaries the word “near” is transcribed as
/ni:r/). Do they mean the same thing?
And in different dictionaries the word “sure” is transcribed as
/ʃu:r/. Do they mean the same thing?
Yes. Whether air is transcribed
/ɛɚ/, it refers to the “standard way air is pronounced in General American English”. Note that the “standard way air is pronounced in General American English” is a slightly fuzzy concept – a number of slightly different pronunciations can be called “standard”.
I don’t think you should assume that dictionary editors prescribe any particular way to pronounce air. Dictionaries have to choose some convention – otherwise, they would have to transcribe air as
/er | ɛr | eər | ɛər/. Remember that the goal of phonetic (or, more precisely, phonemic) transcriptions in dictionaries is to help you group words into classes, so that you know that where belongs to the same class as air, but were does not (even though it has a similar spelling). Transcriptions are not detailed instructions for producing the actual sounds. (As I wrote in my latest update, you shouldn’t take them too literally – instead, you should focus on listening.)
Another thing worth realizing is that people who design phonetic transcription systems for dictionaries like to use the smallest possible number of symbols to keep things simple. So they will transcribe both bed and bear with
/e/, even though bear is usually pronounced with a raised vowel (“raised” means “pronounced with a hint of
[i]”). They just count on you to know that if
/e/ is followed by
/r/, you should raise it a bit. They can get away with this because this “raised
e” vowel always occurs before
/r/ and never before other sounds.
Because of this “symbol overloading”, if you’re trying to use phonetic transcriptions as instructions for pronouncing English sounds, you can be misled.
Have you heard words like “air”, “near” and “sure” with the schwa sound omitted?
The first thing to understand is that the
[r] sound already contains a schwa. When you say
[r], your mouth is in the same position as for
[ə] – the only difference is that your tongue touches the roof of your mouth at the same time. (This similarity is why
[r] is often classified as a semivowel.)
To answer your question, I’d say near is never pronounced with a “clean” schwa in American English. When you say ear, your speech organs first take the position for
[ɪ] (almost closed mouth, tongue in forward position), then they begin changing position (mouth begins to open, tongue moving backwards and curling upwards towards the roof of your mouth). By the time your mouth opens up and your tongue shifts backwards to assume the position for schwa, the tip of your tongue is already on its way to the top of your mouth, resulting in
[r] or something between
[r], which then turns into a real
[r]. In other words, I don’t think there is ever a moment where your mouth makes a clean schwa without any
r-like quality (curled-up tongue). Does this mean that the schwa is omitted? Depends on your definition of a schwa. Is a “schwa with a hint of
r” a schwa or something else?
The same goes for
/ər/ (adder), and
/ɜ:r/ (fur). The last two normally sound like
[fr̩:], respectively. Note the vertical lines which indicate that the
/r/ forms a syllable – it acts as a vowel.
Once again, the lesson here is not to take phonemic transcriptions literally: what looks like a sequence of sounds may actually be one sound.