You learn it in books and in classes. I talk about them in my writing classes--about how to use them properly. I voted okay because if I trip over them, then they annoy the hell out of me. I just read a book that was a romance and there's this climactic scene where the two main characters are sorting themselves out, and every time they spoke, it had a dialog tag that seemed slightly off, and also interrupted the flow. One was the word intoned and it so did not fit the scene at all.

I like using them and having them because they can subtly reinforce a lot of things in the scene, but it's when they are overused that I tend to stumble on them, or when the writer tries so hard to use different ones every time, that they start getting noticeable. And then too, when we travel long driving trips, I'm often the book on tape. I read my husband the Harry Potter novels, and found myself skipping reading a whole lot of the saids because they were accompanied by so many adverbs, that I began to feel self-conscious about them. Weird, huh?