Yes, that is a second clue. The "s" at the end of grandes forms a liaison with écharpes.
It sounds a bit like: il y a de grande-zécharpes.

Taking a closer look, we realize that the little English word "some" has different meanings. It can mean an undetermined (but not large) amount of something. A completely different meaning is to refer to a subset of a larger group, e.g., "some of the dogs are black". It may also be used as an intensifier (that is some dress). In early Duolingo days, there was a push to allegedly help learners by offering an English word to use to translate "des". The problem is that there is no real counterpart in English for the way this "des" is used in French. For this reason, "some" may sometimes be accepted for "des" but it is not generally offered as a natural translation. Example:

• un chien = a dog
• des chiens = dogs (note that it is not "some dogs" because "des" only represents the plural of "un"). Although "some" is occasionally used here, it is almost always ignored in this meaning. I.e., the plural of "dog" is "dogs", not "some dogs".

Now let's introduce an adjective before the plural French noun.

• de petits chiens = small dogs ("des" is shortened to "de" before the plural adjective)
• de grosses pommes = big apples

Other meanings of "some" (certain & quelque):

• à certains moments = at times
• certains d'entre eux = some of them

• ça demande un certain entraînement = it requires some practice ("some" in the sense of an intensifier, in the meaning of "considerable/substantial")

• il y a quelque temps = some time ago

• je voudrais ajouter quelques mots = I'd like to add a few words
• quelques instants = a few moments

A square scarf, i.e., a headscarf, is called un foulard.

Yes, sometimes "de" means "of" or "from" or something else. Here, however, it so obviously can mean "some", it surprpises me that people who are so intelligent missed that when they wrote the sentence. Haste makes waste. Here, "some" is actually the most obvious translation, since "There are large scarves" is basically an incomplete thought. It's almost meaningless. It's like saying, "There are large dogs."

It just seems to obvious to say, "some large scarves", it's quite beyond me how the moderators could miss this. It's not like there's a huge number of possible translations here - there are only two: "There are large scarves" and "There are some large scarves", both equally valid.

If your point is to teach people the basics of the language, then this sentence is a great example of how you show the different treatment "de" gets in this sort of sentence.

This not the same situation as when a particular phrase or sentence can be subject to a wide variety of translations. Someone really dropped the ball on this one, because it's just so simple and obvious.

merci beaucoup :D

While on pronounciation, can you tell me the difference please between Il y a deux grandes écharpes and Il y a de grandes écharpes. I had a type what you hear excercise and more guessed than knew once I had listened several times that it was de and not deux, so did get it correct, but I would like to know what the difference in pronounciation would be. Thanks.