[@shylarah][@NekoMizu]
NekoMizu is right - as I have said, the style and language used in light novels are generally more simplistic compared to standard novels. Using Harry Potter and Nancy Drew as examples provided by Shylarah, you would notice that both titles do have a flair of artistry in the way they structured their sentences, and they can be descriptive. Light novels tend to be more straightforward in the choice of words used (i.e. less use of big words and more of everyday language), dialogue heavy, and descriptions are kept generic/minimal.

I have read a number of light novel books myself - Haruhi Suzumiya series, Shakugan no Shana, Kaze no Stigma, and many more - I do not agree that light novel is a type of narrative fiction where the big plot is stretched over multiple volumes, because this also applies to standard serial novels. I assume that this is a misconception that comes from associating with anime adaptation of the light novels, because anime is usually episodic. Take Haruhi Suzumiya - some of the volumes are actually a collection of short stories (e.g. Sigh, Boredom), which gives an "episodic" feel; some actually do have a plot within one volume itself (e.g. Melancholy, Disappearance). Also, while each Harry Potter book has a complete plot on its own, all of the seven books still come together with one big plot: of how Harry had finally won over Voldemort, the murderer of his parents, and end the Wizarding War for good. Or how about Hunger Games, where it has a big plot spanning over three books with smaller plots in each, instead of just a single volume? The point is, most serial books have both their own plot within that one volume, and also constitute to the bigger plot over the entire series. Using how the plot is being laid out across the volumes isn't an accurate way to determine if the book is considered light or standard novel.