Non-verbal spells were now expected, not only in Defense Against the Dark Arts, but in Charms and Transfiguration too. The older students had taught all the 6th years the trick to nonverbal spells but the other houses hadn't learned it yet. It was a relief to get outside into the greenhouses; they were dealing with more dangerous plants than ever in Herbology, but at least they were still allowed to swear loudly if the Venomous Tentacula seized them unexpectedly from behind.