Looking over past questions posted. Looks like English students are studying the same thing. Glad to say chompchomp helped me a lot,but I have one I keep pondering on.

Jimmy crossed the deep stream by carefully stepping on stones without moss, but he fell twice.
I want to say stepping on stones with stepping a gerund, but the carefully is making me lean toward an adverb not a noun. Help Please!

Since "stepping" is obviously the object of the preposition "by," it must be a noun. It's clear that "carefully" modifies it, so an adverb can modify a gerund.