Sorry, that statement of mine was unintentionally but distinctly misleading. What I intended it to say was, “There are two Hebrew letters that are [placeholders for] vowel-only syllables.” But with it referencing U for “you” and A for the indefinite article in English, I see where I dragged a red gefillteherring through the thread! :o (Three, actually, given vav’s special second use.) Dex did a really nice job on clarifying what it was that I intended to say.