This study explored English language Pedagogical Content Knowledge of secondary school English language beginner teachers in Tanzania on the aspects of self-perceived knowledge, understanding, and classroom teaching practices regarding English language PCK domains namely; English language teaching orientations, English language curriculum materials, English language learners’ learning and English language instructional strategies. A total of 128 secondary school English language beginner teachers were involved from Dar es secondary schools. Simple random sampling and convenient sampling techniques were employed to obtain English language, beginner teachers. Data were collected by using a questionnaire method, semi-structured interview method, documentary review method, and observation method. The analysis of the data revealed that English language beginner teachers' conceptions regarding English language pedagogical content knowledge are partly. This is because despite English language beginner teachers self-perceive as highly knowledgeable and demonstrating good understanding regarding English language PCK, their actual classroom teaching practices are not appropriate. The study concludes that more opportunities should be given through English language teaching method courses during teacher preparation for student teachers to practice teaching activities in the respective PCK domains.