This book presents the study of the English Language with the phonetic and phonological fields, covering the study of the vowel sounds i, thus seeking to analyze the most diverse difficulties that can be found in this field of study, by the students. The aim of this book is to analyze the speech and pronunciations of the phoneme i in the English language, describing the differences between phoneme, allophone and grapheme, identifying the pronunciations of the phoneme /i/ and its respective allophones and establishing the relationship between the grapheme "i" and the phoneme /i/. The book is based on a descriptive study with a quantitative-qualitative approach. In the study, 80% of the participants agreed that there are two sounds expressed as the vowel i. Besides 70% of the girls included in the study are more uninhibited and want to learn in a participatory manner. Thus, it is expected that the development and results of this study encourage the reflection of interested readers about the essentiality of assessing the oral competence of learners from a phonetic-acoustic perspective, a fact that will certainly contribute to the solution of problems concerning the teaching-learning of pronunciation in English.