Recent studies have shown that there is a positive attitude and an increase motivation in the learning of English language by Chadian learners. Despite this, the learners’ linguistic performances remain poor especially in their written productions which are often characterised by grammatical deviances and incomprehensible sentences. This study investigates several kinds of deviances that occur in the structure of English sentences produced by Chadian learners of English as Foreign Language (EFL). The study was carried out using corpora as the method for data collection. Thus, data were drawn from 175authentic narrative paragraphs written by 175Terminale A4 students from Lycée Adoum Dallah, Moundou in Chad. The analyses were based on Interlanguage and Error Analysis Theories. Findings revealed that miss elective errors were the widespread errors committed by Chadian learners of EFL as this category represents 39.17% of deviances.  The results also indicate that sentences produced by Chadian learners of EFL were frequently affected by additive errors (27.76%) and omissionerrors (26.47%). Lastly, the study equally found that misordering errors were less committed as this category of errors represents a small proportion (6.58%) of deviances. These categories of errors were attributed to French language influences and intralingual factors.

The present study aims at investigating the pronunciation components in the prescribed English Language Syllabus for High Schools as well as the pronunciation instruction in some selected High Schools in Moundou, Chad, in order to determine the impact on learners’ production with respect to this phonological feature. The content analysis method was adopted for the investigation. Data were drawn from consultation of the National English Language Syllabus for High Schools in Chad, and 44 English Teachers’ logbooks for the 2021/2022 academic year. These logbooks were collected from 6 Government High Schools in Moundou. Two research questions guided the collection of data which were later on classified, put in numerical data and analysed within the framework of the Factors Affecting Pronunciation Theory. Results of the study revealed a total lack of pronunciation prescription in the English language syllabus and a zero percent representation of pronunciation related lessons in English language classes. Hence, it could be concluded that pronunciation instruction in English language lessons, to a greater extent, has been neglected in some High Schools in Chad. This has created enormous challenges resulting to poor pronunciation, segmental feature errors, and deviances in supra-segments, etc., in the speech production of learners.