Approximant

Definition:

An approximant is a consonant sound produced by bringing two articulators close together without creating the turbulent airflow that characterizes fricatives. Approximants include glides (semivowels like /w/ and /j/) and liquids (/l/ and various r-sounds). They are sonorants — voiced, relatively open, and high on the sonority scale.


In-Depth Explanation

Approximants occupy a middle ground between vowels and true consonants. The articulators approach each other (hence “approximant”) but don’t make contact (that would be a stop or nasal) or create a narrow enough gap for turbulence (that would be a fricative).

SubtypeExamples (English)Examples (Japanese)Description
Glide/w/ (wet), /j/ (yes)/w/ (わ), /j/ (や)Vowel-like, move quickly to the next sound
Lateral approximant/l/ (let)Air flows around sides of tongue
Rhotic approximant/ɹ/ (red)Tongue approaches but doesn’t contact palate

Japanese has two approximants: /w/ and /j/. Notably, Japanese lacks both /l/ and /ɹ/. The Japanese “r” sound is a flap /ɾ/ (the tongue briefly taps the alveolar ridge), not an approximant. This is why the English /l/ vs. /ɹ/ distinction is one of the hardest perceptual challenges for Japanese learners of English — neither English sound matches the Japanese /ɾ/.

For English speakers learning Japanese, the challenge is the reverse: they need to produce /ɾ/ (a quick flap, like the “tt” in American “butter”) instead of their native /ɹ/ or /l/. Producing an English approximant /ɹ/ for Japanese ら行 sounds is one of the most immediately noticeable markers of an English accent in Japanese.

The distribution of approximants in Japanese is restricted by phonotactic rules:

  • /w/ appears only before /a/ in standard Japanese (わ). Historically it appeared before other vowels too (ゐ wi, ゑ we), but these collapsed in modern Japanese.
  • /j/ appears before /a, ɯ, o/ (や, ゆ, よ) but not before /i/ or /e/ in native words.

Related Terms


See Also


Research

  • Ladefoged, P., & Johnson, K. (2014). A Course in Phonetics (7th ed.). Cengage Learning. — Standard reference for approximant classification and articulation.
  • Vance, T. J. (2008). The Sounds of Japanese. Cambridge University Press. — Coverage of /w/, /j/, and the conspicuous absence of lateral and rhotic approximants in Japanese.