The purpose of this study is to find out the causes forrnstudents' deficiency in English with particular reference torngrades 9-12 English curriculum and its implementation inrnschools at capitals of Ethiopian administrative regions.rnTo this effect,data on Grades 9-12 English curriculumrnobjectives and content have been secured with the help ofrncurricular document analyses and unstructured interviews madernwith members of the English Panel in the Institute forrnCurriculum Development and Research(ICDR).rnOn the other hand, information on the curriculumrnimplementation is obtained through questionnaire andrninterviews conducted to grades 9-12 Engl~sh teachers; classrnobservations; instructional media check-lists; assessment ofrncourse and weekly lesson plans, examination and test papersrnin 10 senior secondary schools which have been selected withrnthe help of quota sampling technique.rnThe results of data analyses, interpretations andrndiscussions indicate that one of the causes for students'rndeficiency in English is the design and implementation of therncurriculum, which in accordance to the findings of thisrnpaper, focus on:rnAmbiguity and insufficiency of therncurriculum objectives; absence ofrncommunicative language; high dosage ofrngrammatical descriptions; irrelevance ofrnreading passages ,vocabulary items andrnexercises as curriculum contents andrntheir unsystematic selection andrngradation; shortage and or absence ofrnappropriate instructional facilities,rnplans, methods, techniques and evaluationrnstrategies for implementing it.rnIn synthesis, these findings reveal the pitfalls inrngrades 9-12 English curriculum and its implementation whichrncaused students' deficiency in English; and hoped to servernpolicy makers, the ICDR and teachers as frame of referencesrnto change the curriculum and improve its instruction