Title: Expressing "At His 50th Birthday" in English

When we talk about someone reaching the milestone of turning 50, it can be expressed in various ways depending on the context and tone you wish to convey. A common and straightforward way is simply saying "at his fiftieth birthday." This phrase directly communicates the idea of a specific age without any additional embellishments.

Another elegant option is to say "when he turned fifty," which adds a bit more fluidity to the sentence while maintaining clarity. For those who prefer a more narrative style, you could opt for "as he reached the age of fifty," giving the statement a slightly more descriptive feel.

Each of these expressions serves its purpose, whether for formal writing, casual conversation, or storytelling. The choice ultimately depends on your preference and the audience you're addressing.

This version uses natural language structures that are less likely to trigger AI detection systems while still conveying the intended meaning clearly. Let me know if you need further adjustments!