Language continued to evolve as cultural and technological forces shaped everyday communication, with slang and colloquial expressions becoming especially prominent among Generation Z speakers. This study, titled “Comparison of Gen Z and Non-Gen Z Awareness of Slang and Colloquial Language,” aimed to: (1) assess the level of awareness of slang and colloquial language among Generation Z and non-Generation Z respondents; (2) examine the differences in interpretation and usage of common slang terms between the two groups; (3) identify significant differences in their levels of awareness; and (4) develop instructional material to raise the awareness of non-Generation Z individuals regarding contemporary language forms, particularly slang terms. Using a descriptive-comparative quantitative design, data were gathered from 247 respondents—207 freshmen students from Laguna University–College of Education and 40 non-Gen Z individuals—through pretests, surveys, and workbook evaluations. Pretest results showed that Generation Z respondents achieved a mean score of 25.89 out of 35, indicating high awareness, with a standard deviation of 4.85 reflecting moderate variability due to digital culture and social media exposure. Non-Generation Z participants scored a mean of 9.40, indicating low awareness, with a higher standard deviation of 6.32, suggesting wider variability possibly linked to limited interaction with younger generations. The Mann-Whitney U test confirmed a statistically significant difference (U = 212, p < 0.001), with a large effect size of -0.952, highlighting a substantial generational gap. Key findings emphasized Generation Z’s digital immersion, non-Gen Z’s outdated norms, and the need for targeted interventions. Overall, the results emphasized language’s evolution and the need to bridge awareness gaps for effective, context-aware communication. Based on the findings, the study briefly recommends the refinement and wider dissemination of the workbook to relevant educational and community settings to continue supporting non-Gen Z individuals in navigating evolving linguistic trends.