For vowels in particular, learning to listen to English will often require that the student develop vowel categorizations appropriate for English. English vowels are distinguished by the following characteristics: tongue position and height within the oral cavity, lip rounding or spreading, tension, and gliding (vs. simple vowels). Length is not a distinguishing feature, but instead is influenced by the vowel’s environment (Celce-Murcia, Brinton, & Goodwin, 2010).