Front vowel

Front vowels are a class of vowel sounds used in spoken languages that are produced when the tongue is positioned toward the front of the mouth. Front vowels appear in most of the world's languages, with and being present in 92% and 61% of languages according to PHOIBLE.
Front vowels can be rounded, but are typically unrounded, meaning that the lips are relaxed while speakers are producing them. This is because languages want to maximize the degree of contrast between vowels. Rounding has the effect of bringing a vowel further back in the mouth, so across the world's languages, it's more common for front vowels to be unrounded than rounded, and for back vowels to be rounded rather than unrounded. This is reflected in the position of rounded front vowels on the IPA vowel chart. They are written to the right of the unrounded front vowels to note that they are typically centralized.

Partial list

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, or for a near-close front unrounded vowel.

Articulatory Characteristics

In articulatory phonetics, fronted vowels contrast with raised vowels and retracted vowels. In this conception, fronted vowels are a broader category than those listed in the IPA chart, including central vowels. Within the fronted vowels, vowel height 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, may be fronted to next to or.

Acoustic Characteristics

Acoustically, front vowels have a higher second formant —the second harmonic from the fundamental frequency—than central and back vowels. The second formant corresponds with how far forward the tongue can be positioned relative to the very back of the mouth. Open-front vowels have a lower F2 than close-front vowels because there is less room for the tongue to move forward when the jaw is hinged open.

Effect on preceding consonant

In many languages, front vowels influence the place of articulation of surrounding consonants. In the following examples, front vowels have altered preceding velar and alveolar consonants, bringing their place of articulation towards palatal or postalveolar. These changes often start as allophonic variation, but may become phonemic.
This historical palatalization is reflected in the orthographies of several European languages, including the and of almost all Romance languages, the and in Norwegian, Swedish, Faroese and Icelandic, and the, and 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

	Before back vowel: hard	Before front vowel: soft
English	call	cell
English	gall	gel
French	Calais	cela
French	gare	gel
Greek	γάιδαρος	γη
Greek	Χανιά	χαίρετε
Italian	caro	città
Italian	gatto	gente
Italian	scusa	pesce
Japanese
Japanese
Swedish	karta	kär
Swedish	god	göra
Swedish	skal	skälla