The classification of vowel The height of the tongue raised(high, mid, low The position of the highest part of the tongue(front central, back) The degree of lip-rounding(rounded, unrounded) Oral or nasal Long or short Pure or gliddingThe Classification of Vowel • The height of the tongue raised (high, mid, low) • The position of the highest part of the tongue (front, central, back) • The degree of lip-rounding (rounded, unrounded) • Oral or nasal • Long or short • Pure or glidding