The front vowels that have dedicated symbols in the International Phonetic Alphabet are:
There also are front vowels without dedicated symbols in the IPA:
As above, other front vowels can be indicated with diacritics of relative articulation applied to letters for neighboring vowels, such as ⟨i̞⟩, ⟨e̝⟩ or ⟨ɪ̟⟩ for a near-close front unrounded vowel.
In articulation, fronted vowels, where the tongue moves forward from its resting position, contrast with raised vowels and retracted vowels. In this conception, fronted vowels are a broader category than those listed in the IPA chart, including [ɪ ʏ], [ɨ ʉ], and, marginally, mid-central vowels. Within the fronted vowels, vowel height (open or close) is determined by the position of the jaw, not by the tongue directly. Phonemic raised and retracted vowels may be phonetically fronted by certain consonants, such as palatals and in some languages pharyngeals. For example, /a/ may be fronted to [æ] next to /j/ or /ħ/.2
Main article: Palatalization (sound change)
In the history of many languages, for example French and Japanese, front vowels have altered preceding velar or alveolar consonants, bringing their place of articulation towards palatal or postalveolar. This change can be allophonic variation, or it can have become phonemic.
This historical palatalization is reflected in the orthographies of several European languages, including the ⟨c⟩ and ⟨g⟩ of almost all Romance languages, the ⟨k⟩ and ⟨g⟩ in Norwegian, Swedish, Faroese and Icelandic, and the ⟨κ⟩, ⟨γ⟩ and ⟨χ⟩ in Greek. English follows the French pattern, but without as much regularity. However, for native or early borrowed words affected by palatalization, English has generally altered the spelling after the pronunciation (Examples include cheap, church, cheese, churn from /*k/, and yell, yarn, yearn, yeast from /*ɡ/.)
According to PHOIBLE, /i/ is the most common phonemic front vowel, occurring in around 92% of inventories, while /ɶ/ is the least common, occurring in only one inventory on the database.5
Tsur, Reuven (February 1992). The Poetic Mode of Speech Perception. Duke University Press. p. 20. ISBN 0-8223-1170-4. 0-8223-1170-4 ↩
Scott Moisik, Ewa Czaykowska-Higgins, & John H. Esling (2012) "The Epilaryngeal Articulator: A New Conceptual Tool for Understanding Lingual-Laryngeal Contrasts" https://www.mcgill.ca/mcgwpl/files/mcgwpl/moisik2012.pdf ↩
Palatalization of /si/, /ti/ etc. is shown in spelling in Hepburn romanization. /wiki/Hepburn_romanization ↩
Steven Moran and Daniel McCloy, ed. (2019). PHOIBLE 2.0. Jena: Max Planck Institute for the Science of Human History. https://phoible.org ↩
Of the phonological inventories listed on PHOIBLE, ɶ only occurs in Northern Altai /wiki/Northern_Altai ↩