if an epithet adjective precedes its noun and it doesn't form a compound word with it, you will use 'de' instead of 'des'. Par example : - Des + nom + adj : Il me faut des chaussures nouvelles - De + adj + nom : Il me faut de nouvelles chaussures - Il a des pieds énormes / Il a d'énormes pieds Concerning 'très', it's is just an adverb, which is usually used before an adjective or an adverb. - Il a des problèmes sérieux / Il a de sérieux problèmes - Il a des problèmes très sérieux / Il a de très sérieux problèmes

Well, I would have *said* that, but not written it. As Green explains, "de + adj. + noun" is the correct form. But to Canadian ears, it sounds a little weird, so we don't change "des" to "de" in that situation. Of course, we know it's the proper way to write it. It's just a question of the differences between written and spoken French.

I would have written des as well. Very interesting question!