“Reason” in this sense, according to the Oxford English Dictionary, is commonly used with “why,” “that,” “for,” or an infinitive. The noun “reason” in this usage means “cause” or “the thing that makes some fact intelligible,” Merriam-Webster’s says. In this expression, “why” is a conjunction and means “for which” or “on account of which,” according to Merriam-Webster’s Collegiate Dictionary (11th ed.). As the earlier post points out, the words “reason” and “why” here aren’t redundant. We’ve written about this before on our blog. Merriam-Webster’s Dictionary of English Usage uses it as well, as when the editors reach this conclusion on an unrelated matter: “There is no reason why you need to avoid this usage.” Q: Whence comes the ubiquitous redundancy “the reason why”? Isn’t “reason” itself sufficient to the task?Ī: Yes, “reason” is sufficient to the task, but we see nothing wrong with “reason why.” In fact, we sometimes use the phrase on our blog.
