Journal ArticleThis paper presents a classroom-based research on input simplification and interactional modification strategies used by English language teachers to make their oral input comprehensible to their learners. The main objective was to examine the input simplification and interactional modification strategies used by English language teachers in EFL classrooms, focusing on lexical and syntactical aspects of the language. Data were collected from four English language teachers and 183 students from four selected classrooms and a review of English language syllabi in Tanzania. The study was carried out by means of audio recordings, classroom observations and interviews.The findings show that teachers employ different linguistic simplifications and interactional modification strategies in EFL classrooms to enhance students‟ comprehension and interlanguage development. The findings further revealed that the use of input simplification and interactional modification strategies is crucial for students‟ comprehension and language development. A combination of factors - personal style of teaching, lesson content, methodology, students‟ proficiency level and linguistic background - was found to influence foreigner talk(FT) strategies. In the present paper, it is recommended that linguistic simplifications and interactional modification strategies in EFL classrooms be systematically used and streamlined in the methodology of teaching EFL. The authors also recommend that the knowledge of native speakers' (NS) / non native Speakers' (NNS) discourse for various contexts, tasks and addressees need to be explored to establish triggers of FT, and then discover which discourse modifications, if any, actually facilitate foreign language learning.