This study investigates the effects of bilingualism on cognitive processes in younger (20 years) and older (68 years) adults, comparing monolingual and bilingual participants. The tasks assessed working memory, lexical retrieval, and executive control. Younger participants generally performed better than older participants, confirming the impact of aging. Monolinguals and bilinguals showed similar performance in working memory tasks, with monolinguals outperforming bilinguals in lexical retrieval tasks, and bilinguals performing better in executive control tasks. Older bilinguals exhibited larger language group differences in executive control tasks. The findings replicate previous studies and suggest that bilingualism enhances executive control and may protect against cognitive decline in older adults, while also affecting lexical retrieval more negatively. The study discusses how managing two language systems leads to these different outcomes in cognitive and linguistic functions.This study investigates the effects of bilingualism on cognitive processes in younger (20 years) and older (68 years) adults, comparing monolingual and bilingual participants. The tasks assessed working memory, lexical retrieval, and executive control. Younger participants generally performed better than older participants, confirming the impact of aging. Monolinguals and bilinguals showed similar performance in working memory tasks, with monolinguals outperforming bilinguals in lexical retrieval tasks, and bilinguals performing better in executive control tasks. Older bilinguals exhibited larger language group differences in executive control tasks. The findings replicate previous studies and suggest that bilingualism enhances executive control and may protect against cognitive decline in older adults, while also affecting lexical retrieval more negatively. The study discusses how managing two language systems leads to these different outcomes in cognitive and linguistic functions.