Odhiambo, Juma Elisha2021-10-042021-10-042021-082394-9694http://repository.rongovarsity.ac.ke/handle/123456789/2353Code-mixing and code-switching allude to alternating between two or more languages. Any Kenyan student undergoing an 8-4-4 system of education attests to getting exposed to at least two languages—English and Kiswahili languages. While the English language is the primary language of instruction in Kenyan secondary schools, using the Kiswahili language between English-based lessons prevails. For Kenyans, the English language is best used where foreigners are involved, limiting using local languages to address. In that line, teachers and students often alternated between English and Kiswahili during learning to enhance clarity and participation. Because Kenyan parents want the best out of their children's education, any teacher who is strict about using the English language during instruction is regarded as role model teacher by both students and parents. In schools where alternating between English language and Kiswahili language permeated while learning the English language as a subject, students experienced limited exposure to linguistic repertoires in the English language. On the other hand, schools that primarily use English for instruction have their students advancing their vocabularies in the English language. That is why the paper examines the effects of code-mixing and code-switching on the study of the English language, a case for Homa- Bay County. In other words, the study evaluates influencers to language alternation, suppose code-mixing and code-switching contribute to students' failure or success, and remedy to the educational gap. A qualitative approach was utilized during data collection, analysis, and presentation. The researcher realized that code-mixing and code-switching directly influenced students' failure to pass the English language as a subject. Regardless, it also led to a lack of confidence during a conversation and retarded mastery of linguistic repertoires. It is therefore recommended that regular interventions such as internships and development programs for both teachers and students would enhance the English language study significantly.enAttribution-NonCommercial-ShareAlike 3.0 United Stateshttp://creativecommons.org/licenses/by-nc-sa/3.0/us/Code-mixing, Code-Switching, English language, Kiswahili language, Language alternation.Article