Positive:
* Her relentless pursuit of knowledge led her to become a renowned scientist. (Emphasis on determination)
* The team's relentless effort paid off, securing them a victory in the final game. (Emphasis on perseverance)
Negative:
* The relentless heat made it impossible to enjoy the outdoor festival. (Emphasis on persistence that is undesirable)
* His relentless criticism wore down her confidence. (Emphasis on negativity)
Neutral:
* The relentless waves crashed against the rocky shore, a constant reminder of nature's power. (Emphasis on a force that continues without stopping)
* The relentless march of time seemed to accelerate as she grew older. (Emphasis on the constant and unchanging nature of something)
The meaning of "relentless" can vary depending on the context. Think about what you want to emphasize when choosing how to use it.