I recently answered a question on Quora, but latterly realized that my observation might well be unique ‒ and, indeed, a quick Googling did not reveal anyone else who had cottoned on to it.
When we were reading The Lord of the Rings aloud to our daughters while on our car trips, I came to the passages set in Rohan just after having read Beowulf in the bilingual edition of the Seamus Heaney translation ‒ of course, I am only slightly familiar with Anglo-Saxon, but enough to catch words now and then.
It is well known, I think, that Tolkien was an Anglo-Saxon scholar, and that he based the culture of the Rohirrim on that of the Anglo-Saxons.
What I realized, reading the dialogue aloud, was that Tolkien had expunged all traces of Greek and Latin from the words the Rohirrim speak. This is what gives their speech its unique flavor ‒ and is quite a difficult thing to do. If you read back through what I have written here, you will see many a word derived from those sources (usually via French, of course). Of course, I'm not trying ‒ but if I were, this post would take a couple of days to write rather than a few minutes.