I'm a university student studying sound structure. It's a first-year course. No matter how many times it's explained to me in lectures, tutorials, help labs, or office hours -- I don't understand all the circumstances that I would use one over the other.

/ / = phone, phoneme, mental grammar versus [ ] = after processes have been applied, phonetic

But, when I look online, even if processes have been applied to a name, for example -- it's still showing as / /, such as: 'Yasiin Bey' /jæˈsiːn ˈbeɪ/ instead of [jæˈsiːn ˈbeɪ].

What am I not understanding?


2 Answers 2


There are two slightly different conventions for the use of these symbols.

In phonetics—the study of the actual sounds produced by the vocal tract, transmitted through the air, and received by the ear—slashes are used for a broader transcription and brackets for a narrower transcription. In other words, a transcription in brackets will generally include finer details than a transcription in slashes.

In phonology—the study of the mental representation of those sounds—slashes are used for phonemes and brackets are used for phones. In other words, a transcription in slashes refers to the theoretical mental representation of an utterance, and a transcription in brackets refers to how it's actually produced on the phonetic level.

People (including me) often use both of these conventions freely without specifying which one is in effect, unless it's important to specify that they're talking specifically about phonology rather than phonetics, or vice versa.

  • 2
    Even a broad phonetic transcription would conventionally be in square brackets rather than slashes.
    – Miztli
    Apr 11, 2022 at 9:35
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    @Miztli Not so. For example, not in the International Phoneticc Association exam. Especially the case where language-specific transcription symbols are used (as opposed to faithfully using the IPA system). For example, a broad phonetic transcription might give /hʌt/ for hut, whereas a square brackets one would have to be [hɐt]. Apr 11, 2022 at 11:40
  • +1 Might be worth mentioning that those broad transcriptions often use language-specific transcription systems as opposed to the international IPA system. (Alternatively might be better to keep it simple, as you have done. Not sure). Apr 11, 2022 at 11:41
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    What Miztli said. Narrowness is independent of the phonemic–phonetic dichotomy. Slashes denote a phonemic transcription, which is by definition always broad, while phonetic transcriptions range from broad to narrow (see Handbook of the IPA, pp. 28–30).
    – Nardog
    Apr 11, 2022 at 12:37
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    Nothing about this answer is incorrect or badly worded, but I do think it would help general clarity (esp if this is going to be the established answer for this question) if you have time in the next few days to give some concrete examples for both parts of both categories in practice.
    – lly
    Apr 11, 2022 at 17:33

First, there are different standards as to the meaning of these brackets. Second, some people don't follow these standards. The general trend on the use of these brackets is that /xyz/ is "deeper, more abstract" and [xyz] is "closer to physical realization". But there are very many levels of analysis, so some people may use /xyx/ to represent "the phonemic analysis" and others use it to refer to "the underlying form", or else "something that isn't the phonetic form".

On the end close to physical production, [xyz] might be the last phonological representation, or it might be the last linguistic representation (thus the phonetic representation), or it might be the actual physical form (since phonetics is still part of linguistics, not physics). It is often very difficult to figure out is an author means anything specific my the use of those brackets.

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