This has confused me in both youth and adulthood for completely different reasons.

My first time reading these books, I knew just enough to be sure a single robe covered the entire body and wondered why someone would wear more than one. I then grew old enough to appreciate the concept of multiple layers and assumed that to be what Rowling meant.

As an adult, I’m less sure:

Robes is a countable noun and can refer to either a singular or plural, which means Rowling could feasibly have meant that wizards wear a single robe. Given the existence of magic, I would think wearing one robe might be more practical. The primary reason for wearing multiple would be in the pursuit of warmth, since robes tend to let through even faint breezes and would offer almost no resistance against the elements.

With magic in play though, I’m not sure this matters. Getting a robe that keeps its wearer warm and is resistant to wind and rain seems very plausible. Maybe they’re expensive, but seeing as a third-year Hermione knew the impervious charm, I can’t imagine they’re difficult to make, which must impact the price.

That leaves me assuming, in at least most cases, Rowling may have just used the noun with the intention of referring to a singular robe as opposed to more than one.

Though that is the formal usage, speaking both historically as well as linguistically, and some might say that makes it an odd choice inside a children’s series.

My take is that Rowling probably meant one robe and that her reasoning for choosing to use ‘robes’ probably came down to the fact it’s easier to just say ‘wearing robes’ than to work some iteration of a ‘a robe’ into sentences.

I’ll note here that there is also the possibility she used ‘robes’ because some chose to wear one layer, whereas others wore multiple. In this case, ‘robes’ could be a more elegant solution than delineating on a case by case basis, though I would somewhat push back on that and say subtle character work could be done by delineating.

I’m personally not a huge fan of ‘robes’, either way. If it’s meant to imply multiple layers, I question why. If it’s meant to be singular, I think it muddies the clarity without a good reason for doing so.

Which leaves me two questions:

1 - Given that it could mean singular or plural from a linguistic standpoint, which do you think Rowling intended us to infer?

2 - Do you think using ‘robe’ instead of robes would standout in a negative way when reading fanfiction? I’m curious because I’m leaning toward using the objective singular in the story I’ve been prodding at.

 

robes = clothes

robe = a specific item of clothing

That's how I understand it.

 

I doubt she put much thought into it, and just used robe and robes interchangeably depending on what flowed better in the sentence that she was writing.

At least my impression was that the terms were used interchangeably.

 

I like this explanation if you ignore a number of contradictory passages throughout the series—IE Rowling regularly referring to t-shirts as an additional layer of clothing alongside ‘robes’, and similar such examples.