Editing International Phonetic Alphabet (section)

=== Letter forms ===
[[File:LowercaseG.svg|right|thumb|Loop-tail {{angbr IPA|g}} and open-tail {{angbr IPA|ɡ}} are graphic variants. Open-tail {{angbr IPA|ɡ}} was the original IPA symbol, but both are now considered correct. See [[history of the IPA]] for details.]]
The letters chosen for the IPA are meant to harmonize with the [[Latin alphabet]].{{NoteTag|"The non-roman letters of the International Phonetic Alphabet have been designed as far as possible to harmonize well with the roman letters. The Association does not recognize makeshift letters; It recognizes only letters which have been carefully cut so as to be in harmony with the other letters."<ref>{{harv|International Phonetic Association|1949}}</ref>}} For this reason, most letters are either [[Latin script|Latin]] or [[Greek alphabet|Greek]], or modifications thereof. Some letters are neither: for example, the letter denoting the [[glottal stop]], {{angbr IPA|ʔ}}, originally had the form of a [[question mark]] with the dot removed. A few letters, such as that of the [[voiced pharyngeal fricative]], {{angbr IPA|ʕ}}, were inspired by other writing systems (in this case, the [[Arabic script|Arabic]] letter {{angbr|[[Ayin|ﻉ]]}}, ''{{transliteration|ar|ʿayn}}'', via the reversed apostrophe).<ref name=Pullum />
<!--clearly, ʔ and ʕ are not of independent origin and reflect the transliteration of alif vs. ayin in Semitic philology. Source needed-->

Some letter forms derive from existing letters:
* The right-swinging tail, as in {{angbr IPA|ʈ ɖ ɳ ɽ ʂ ʐ ɻ ɭ&thinsp;}}, indicates [[retroflex]] articulation. It originates from the hook of an ''r''.
* The top hook, as in {{angbr IPA|ɠ ɗ ɓ}}, indicates [[glottalic ingressive|implosion]].
* Several [[nasal consonant]]s are based on the form {{angbr IPA|n}}: {{angbr IPA|n ɲ ɳ ŋ}}. {{angbr IPA|ɲ}} and {{angbr IPA|ŋ}} derive from [[Typographic ligature|ligatures]] of ''gn'' and ''ng,'' and {{angbr IPA|ɱ}} is an ''ad hoc'' imitation of {{angbr IPA|ŋ}}.
* Letters turned 180 degrees for suggestive shapes, such as {{angbr IPA|ɐ ɔ ə ɟ ɥ ɯ ɹ ʌ ʍ ʎ}} from {{angbr IPA|a c e f h m r v w y}}.{{NoteTag|Originally, {{IPA|[ʊ]}} was written as a small capital U. However, this was not easy to read, and so it was replaced with a turned small capital omega. In modern typefaces, it often has its own design, called a "horseshoe".}} Either the original letter may be reminiscent of the target sound, e.g., {{angbr IPA|ɐ ə ɹ ʍ}}{{snd}}or the turned one, e.g., {{angbr IPA|ɔ ɟ ɥ ɯ ʌ ʎ}} recall ''o j y u/w ᴀ y/λ''. Rotation was popular in the era of [[mechanical typesetting]], as it had the advantage of not requiring the casting of special type for IPA symbols, much as the sorts had traditionally often pulled double duty for {{angbr|b}} and {{angbr|q}}, {{angbr|d}} and {{angbr|p}}, {{angbr|n}} and {{angbr|u}}, {{angbr|6}} and {{angbr|9}} to reduce cost.
*:[[File:Turned small cap omega as a vowel.png|thumb|An example of a font that uses turned small-capital omega {{angbr|ꭥ}} for the vowel letter ''ʊ''. The symbol had originally been a small-capital {{angbr|ᴜ}}.]]
* Among consonant letters, the [[small capital]] letters {{angbr IPA|ɢ ʜ ʟ ɴ ʀ ʁ}}, and also {{angbr IPA|ꞯ}} in [[extIPA]], indicate more [[guttural]] sounds than their base letters{{snd}}{{angbr IPA|ʙ}}<!--for the bilabial trill--> is a late exception. Among vowel letters, small capitals indicate [[lax vowel]]s. By 1947, the original small-cap vowel letters {{IPA|⟨ᴀ}} <big><sub><span style="{{Transform-rotate|180}}">{{IPA|ᴀ}}</span></sub></big> {{IPA|ɪ ᴜ⟩}} had been replaced by {{angbr IPA|ʌ ɤ ɩ ɷ/ʊ}}, with only {{angbr IPA|ʏ}} remaining as a small capital, though later {{angbr IPA|ɪ}} and {{angbr IPA|ɶ}} would be restored.