In North American English (NAE) and British English, [ae] and [open back unrounded vowel] are open vowel phonemes which are articulated by a speaker easily without a build-up of air pressure. Among all English vowels, the greatest problem for most Turkish majors of English is the discrimination of [ae] and [open back unrounded vowel]. In English, [ae] is called the "short a" or ash, and [open back unrounded vowel] is termed as "short o" or "script-a," which has a soft nature in its pronunciation. [Open back unrounded vowel] exists in Danish, Norwegian, and Swedish. In addition, it exists in French vowel system, as in "temps" (time) and "banc" (bench). It is commonly known that non-native speakers of a language, such as Turks, who cannot hear different sounds, are probably not pronouncing [ae] and [open back unrounded vowel] sounds correctly. The aim of this study is to uncover the difficult phonetic details of English [ae] and [open back unrounded vowel] sounds for Turkish English majors, and teachers-on-the-job and propose a sample lesson plan to them.