This book addresses speech intelligibility problems with Sudanese Arabic (SA)-accented English. It measures the intelligibility of Sudanese EFL learners for native British and American listeners/speakers, besides Dutch listeners who use English as a lingua franca. The objective of the study is to find experimental evidence in relation to the causes of the problems at issue. The study examined vowels and consonants of English on isolated words and words on sentence context. The study comprised three experiments including perception, pronunciation and written questionnaires. Comparison of Sudanese EFL learners' findings to those of the native listeners/speakers of English revealed substantial differences between the perception and pronunciation of non-native and native varieties. The results of the questionnaires showed correspondence to the findings of experiments. The overall results revealed degraded intelligibility of Sudanese Arabic accented English due to different factors. This book is of relevance to linguists and language teachers. It focuses on English pronunciation, phonology and phonetics to university students with an Arabic native language background.