This paper is set out to examine the systematic developmental features in the acquisition of the English article system by Luhya L1 learners in secondary schools, conducted in Vihiga County, Kenya. Even though English plays a central role in Kenya’s education system, there is still a dearth of research on how Luhya speaking learners really learn how to use the English system in secondary schools in Vihiga County, Kenya. There isn’t a clear picture on the stages these learners go through or the various errors that stick around for a long time. This kind of insight will enable tea teachers and curriculum developers to provide interventions which meet the needs of these learners. The objective of the study was to examine the systematic developmental features in the acquisition of the English article system by Luhya L1 Learners. The study was guided by Fluctuation Hypothesis which was used to predict and explain the systematic errors of L2 learners and Full transfer /Full access hypothesis according to which in the learning process the L2 learner transfers the entire L1 grammar on to L2. The study adopted a pragmatic paradigm and a case study design to explain how learners construct their knowledge of L2 English article system in the context of L1 Luhya that is linguistically different from English. A mixed method approach was employed to allow for the use of both quantitative and qualitative methodologies leading to a better understanding of the article use phenomenon. The study sample included 6 schools purposively selected from three sub-counties and 24 students of English from these schools. The data collection instrument was a multiple-choice task. The data was analysed using descriptive statistics and content and thematic analysis procedures. The study revealed various developmental features which included: overuse, fluctuation, and omission errors. In the light of the study findings, it was concluded that the pedagogy utilized in the instruction of the English article is flawed, there is minimum content coverage for the English article and that both learners’ L1 and L2 negatively influence the acquisition and learning of English article. Thus, it is recommended that teachers adopt an eclectic approach in teaching the English article system and that the curriculum developers review the English language syllabus with regard to the article system and accord it the prominence it deserves. Theoretically, the study contributes to the advancement of knowledge about the teaching of the English article system. Practically, curriculum developers should find the study useful and reconsider revising the English language curriculum reconsidering content overage at the various levels of learning, factoring in elements that would facilitate SLA and SL learning.