Frontness

Frontness, in phonetics and phonology, refers to the horizontal position of the tongue during articulation, specifically how far forward in the oral cavity the tongue is directed. It is often paired with the concept of backness (the rearward position) to describe the articulation of vowels and, less commonly, consonants. In vowel descriptions, frontness (also called advancement) characterizes the tongue body position. Front vowels, such as those typical in many languages, are produced with the tongue body forward in the mouth, while back vowels are produced with the tongue retracted toward the back. Central vowels occupy an intermediate position between front and back. Phonological analyses frequently encode frontness as a binary feature [+front] or [-front], though the precise inventory can vary by framework.

The frontness of vowels tends to interact with lip rounding and with tongue height. For example, in many languages high front vowels are unrounded, while some high front vowels may be rounded in others. Frontness contrasts contribute to vowel inventories and can participate in processes such as vowel harmony or vowel shifts, whereby a vowel in a word changes frontness to match the surrounding vowels.

In reference to consonants, frontness is less commonly treated as a distinct feature than place of articulation in the front-to-back dimension (for example, bilabial, dental, alveolar, palatal are anterior), but articulatory descriptions still distinguish more forward from more rearward articulations.

Summary: Frontness is a foundational dimension for describing vowel quality and certain phonological patterns, providing a parallel to backness and other articulatory features used in linguistic analysis.