This book highlights the learner, environmental and pedagogic factors that affect the learning of some phonological and grammatical aspects of English by speakers of other languages. The study was carried out on a sample of 485 second cycle (6th and 7th year) students and 189 English-as-Foreign-Language (EFL) teachers. The students and teachers were from monolingual technical secondary schools (MTS), monolingual general secondary schools (MGS), bilingual general secondary schools in Francophone environments (BGSF) and bilingual general secondary schools in an Anglophone environment (BGSA). The simple random and purposive sampling techniques were used to obtain the elements of the study. Grammar and pronunciation tests as well as a questionnaire were administered on the learners and just a questionnaire on the EFL teachers. The descriptive statistical method was used and percentages, means as well as the standard deviations of the scores, were worked out and presented on tables and figures. This book is a must-buy-it for English language teachers, teacher trainers and teacher-trainees worldwide. It is equally an invaluable handbook for English language policy makers.