Department of Educational Psychology & Science, School of Education,
Rongo University, Kenya

Email: duncanothoo@gmail.com

Abstract: Kiswahili has evolved significantly since the eighteenth century and is now recognized as a key language for national integration and development in Kenya. Consistent with the Languages of Kenya Policy (2010), effective Kiswahili instruction remains central to educational outcomes. This study examined the influence of teacher motivation on learners’ performance in Kiswahili in public day secondary schools in Suba South Sub-County, Homa Bay County, Kenya. Guided by McCrae and Costa’s Five-Factor Theory of Personality, the study adopted a mixed-methods approach using a descriptive survey design. The target population comprised 210 participants, including Kiswahili teachers, principals, and deputy principals. Purposive sampling yielded 47 teachers and 28 principals as main respondents, while 28 deputy principals served as key informants. Quantitative data were collected through questionnaires and analyzed using descriptive statistics, while qualitative data were obtained through interviews and analyzed thematically. Instrument validity was established through expert review, and reliability was confirmed using the test-retest method (r = 0.7513). The findings revealed a strong and statistically significant positive relationship between teacher motivation and learners’ performance in Kiswahili (r = 0.627, p < .001). The study recommends enhanced recognition, promotion, and continuous professional development to strengthen teacher motivation and improve learner performance.