At least "do the needful" is somewhat correct and parseable. It was even used in Victorian England.[1] Anyone can understand it means "do what's necessary". It'

At least "do the needful" is somewhat correct and parseable. It was even used in Victorian England.[1] Anyone can understand it means "do what's necessary". It's old and weird, but not wrong. "revert" and "reply" are entirely different words that sound kind of similar. 1. https://www.grammarly.com/blog/do-the-needful/ https://www.grammarly.com/blog/do-the-needful/