What is the difference between “ɪ”, "i", “i:”? Are these two same “ɪ”, "i" and won't be wrong if interchanged while transcripting? For example: Is it correct to write either /ʃɪp/ or /ʃip/ in case of IPA transciption of the word "Ship"?

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    They are distinguished in English and can't be substituted. /ʃɪp/ means ship and /ʃip/ means sheep. Spanish speakers have problems with that, because the two vowels are not phonemic is Spanish, and one can often swap them with no problems. Apr 4, 2023 at 17:34
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    One note: as I recall, /i/ and /iː/ are pronounced identically in most AmE and BrE dialects; dictionaries consider them separate phonemes because some dialects, like those that lack the usual "happy"-tensing, do have a difference in pronunciation there.
    – alphabet
    Apr 4, 2023 at 21:32
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    @alphabet They aren’t considered different phonemes. Apr 4, 2023 at 21:51
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    @alphabet In certain weak syllables (open unstressed syllables) there is variation between speakers of British English in terms of whether they use /ɪ/ or /i:/, with some much older speakers often preferring /ɪ/ and a vast majority of younger speakers using /i:/. The /i/ symbol merely means "may be pronounced with either /ɪ/ or /i:/" Apr 4, 2023 at 22:22
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    @Araucaria-Nothereanymore. There are no minimal pairs /i/ and /i:/ and thus length is not phonemic in this hypothetical pair. But people don't "like" to write [ɪj] for the FLEECE vowel. Some transcribers elect to distinguish infinitesimally tiny phonetic aspects to try to help give foreigners the little finishing touches that make English sound like English, while others paint with a broader, more inclusive brush leaving the final finishing feather-stitching as an exercise for the native speaker familiar with his own phonology. This superabundance of different styles harms more than it helps.
    – tchrist
    Apr 5, 2023 at 14:03

3 Answers 3


John Lawler wrote in comment:

They are distinguished in English and can't be substituted. /ʃɪp/ means ship and /ʃip/ means sheep. Spanish speakers have problems with that, because the two vowels are not phonemic is Spanish, and one can often swap them with no problems.

  • I am new to learning IPA so even though I know the pronunciation of ship or sheep I had problem decoding them.Besides our teacher, she wrote /ʃip/ for ship and next day corrected it but didn't say anything about the existence of /i/.And for Sheep I knew it is /ʃi:p/.So can long e be written either as /i/ or /i:/?
    – Dia
    Apr 5, 2023 at 10:26
  • google.com/… In this video /i/ is also included in IPA and seems a separate one.But I didn't find in any other sites and only /i:/ and /ɪ/ are always shown.Does /i/ exist as a separate item or is it same as /i:/ and interchangeable??
    – Dia
    Apr 5, 2023 at 10:30

<i> has been used to represent both the vowels in ship and sheep. You can never tell what sound an IPA symbol represents just by looking at it by itself, because there are competing conventions. You have to look at what words it's used to represent or what other symbols are used in the same system. As the Handbook of the International Phonetic Association (1999: 30) puts it:

[T]he contrast between the words bead and bid has phonetic correlates in both vowel quality and vowel duration. A phonemic representation which explicitly notes this might use the symbols /iː/ and /ɪ/ ... But it is equally possible unambiguously to represent these phonemes as /iː/ and /i/ ..., or as /i/ and /ɪ/ ... All three pairs of symbols are in accord with the principles of the IPA ... The IPA does not provide a phonological analysis for a particular language, let alone a single 'correct' transcription, but rather the resources to express any analysis so that it is widely understood.

The three types of notation (/iː/–/ɪ/, /iː/–/i/, and /i/–/ɪ/) are known as "qualitative-quantitative", "quantitative", and "qualitative", respectively. The quantitative and qualitative transcriptions coexisted for a long time, but the latter is usually favored in North America because the contrast in duration is not as robust there as in England. In the UK, the quantitative type used to be popular, but has largely been replaced by the qualitative-quantitative since around 1970.

The quantitative notation was used in highly influential publications such as Daniel Jones's English Pronouncing Dictionary (1917)—hence also known as the "Jonesian" notation—and the first editions of the Oxford Advanced Learner's Dictionary (1948), so you might still encounter it especially in educational material such as bilingual dictionaries, even though recent publications coming directly out of the UK overwhelmingly use the qualitative-quantitative, or "Gimsonian", notation, which was formalized by A.C. Gimson, who succeeded Jones.

Few if any American dictionaries aimed at native speakers use IPA, but learner's dictionaries from the US tend to opt for the qualitative system.

An additional complication unique to this trio of symbols is that some qualitative-quantitative conventions employ all three of them. In such a system, <i> refers to a situation, typically exemplified by happy, where it used to be pronounced by a majority like /ɪ/ until some time in the 20th century but now it's most often pronounced like /iː/. This does not mean that there is a separate sound; it just means "/iː/ or /ɪ/", and for most modern learners it can be equated with /iː/. See this Wikipedia section for more.

  • +1 Nice to see an accurate description of the HAPPY vowel. I think your first paragraph could be made even better/clearer if it said “In a language-specific phonemic transcription system, you can never tell …*”. The same kind of generalisation is not true of narrow purely phonetic transcriptions using the IPA in its original intended use. Apr 7, 2023 at 11:04
  • Phonemic transcription IS the IPA's original intended use since 1888. And since narrowness is a continuum, even in allophonic transcriptions you can never tell what sound each symbol represents without acquainting yourself with the underlying conventions either. See the IPA Handbook.
    – Nardog
    Apr 7, 2023 at 11:22
  • You don't need any knowledge of the language concerned or of the language specific conventions to understand a purely phonetic narrow/square brackets transcription. And you need know nothing to write one either. The comments from the IPA handbook re i and ɪ apply only to the language-specific conventional system; they do not apply to symbols used for narrow transcription. So for example, the language specific phonemic system may use ʌ for the STRUT vowel, but this would be completely inadmissible in a narrow transcription where something like [ɐ] would have to be used. Apr 7, 2023 at 12:17
  • Not all transcriptions enclosed in square brackets are impressionistic, i.e. "purely phonetic". They rarely are. Most of them are allophonic, and range from broad to narrow. Again consult the Handbook, particularly pp. 28-30.
    – Nardog
    Apr 7, 2023 at 13:29

"i", “i:” have the same quality in IPA symbols; this means that on the diagrams of pronunciation (back-front vs open-close) they are found at the same place (front (front of the mouth), close (mouth closed) ; the only difference is the length. “ɪ” is pronounced with the mouth less closed and not so near to the front.

                                              enter image description here

IPA chart

No, it is not correct to write either /ʃɪp/ or /ʃip/ in case of IPA transcription of the word "Ship". The only pronunciation is /ʃɪp/.

You might find "i" in "sheep" instead of "i:", this being so because of so called pre-fortis clipping (/p,t,k,f,θ,s,ʃ,tʃ/ the fortis consonants make the vowel shorter).

  • I think you may be confusing phonetics and phonemics; the phonemes /ɪ/ and /i/ may or may not correspond to the sounds [ɪ] and [i].
    – alphabet
    Apr 4, 2023 at 22:50
  • @alphabet I don't see how that is relevant in the present discussion. Moreover, I never thought that there was a significant phonological variety in the pronunciation of the phoneme /i:/. There is such a significant variety for instance in the pronunciation of the phoneme /k/ ; /kɑːt/ → [kʰɑːt], /skɑː/ → [skɑː], (cart, scar). Otherwise, where do you find something wrong in the above answer?
    – LPH
    Apr 4, 2023 at 23:28
  • I'm with @alphabet : it's not helpful to confuse readers by making them think that the language specific symbols used for transcribing English relate directly to the values of the IPA, especially for vowels. Apr 5, 2023 at 8:31
  • Hmmm. Something going wrong with your font here. The bad and good transcriptions for ship are identical! (and all correct) Apr 5, 2023 at 9:54
  • @Araucaria-Nothereanymore. I've checked both the source code and the post and there is no error in my interface.
    – LPH
    Apr 5, 2023 at 10:00

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