Why do we distinguish whether a word in English comes from French or Latin, when French itself evolved from Latin?

Answer 1

One area in which it can be known is in the dictionary entries of American Noah Webster vs those of Samuel Johnson on the same words. We can tell by spelling, with Johnson preferring spelling tending to the French.

Answer 2

To put it short, it helps better explain the etymology, meaning, and connotations of a word.

Languages are living and breathing, and words evolve over time even within the same language; for example, in Greek, the word "daemon," which means "divine spirit," originally had a neutral connotation, but the rise of Christianity saw it take on a negative sense, eventually evolving into the word that becomes "demon" in English referring to evil spirits. And this transformation happens within the Greek language alone!

The evolution of Latin into its constituent languages happened in part because of regional dialects and interactions with pre-existing local languages (e.g., Gaulish in France) and the imposition of Germanic languages on these local dialects (the Frankish dialect of German in France, the Visigothic one in Spain, etc.). Not only did these languages cause shifts in word usage and connotations of preexisting Latin words, they also introduced new words into the language. Thus, a word that comes into English from French might not even have a Latin root!

Even so, if a word has a Latin root, specifying whether the word comes from French or Latin gives a little bit of insight into whether the word went through this evolution, without telling the entire etymological history of the word.