This poem is fairly simple on the surface, but it also deals with some heady, conceptual territory. There are some obscure vocabulary words, but it's basically pretty straightforward in that sense. Coleridge is trying to write in eloquent and polished English, but he's not attempting to reinvent the alphabet or anything (there's no super-literary hijinks going on). "Frost at Midnight" is a little difficult, though, because of its ideas and images. Without a little guidance, it's hard to immediately understand what Coleridge means by Nature's "eternal language," or to grasp what the frost imagery symbolizes or suggests.