You have to love a poem that opens with the word, "Well," as if the writer were just letting off steam. Think of a poem that begins, "Well, this stinks," and you'll have an idea of the tone that he's after. The speaker is pouring out a complicated brew of emotions, including frustration, astonishment, and brotherly love, but he does so within the confines of a specific poetic meter, blank verse. To use an analogy, imagine trying to discuss a topic of deep emotional significance without using the letters "M" or "R". It's a completely arbitrary rule, but it forces you to structure your thought…um…we mean…"it tasks you with the challenge of putting thoughts within a specific design" (no "Ms" or "Rs," phew!). Blank verse could be summarized as the poetic meter that is formal…but not too formal.
On the page, the poem has a somewhat uneven appearance: lines carry over from one line to the next without punctuation, and the stanzas chop off mid-line. But to your trained poetic ear (we know you've got one), you'll hear a kind of structure that your eye doesn't catch. For example, certain sections of the poem focus on particular letters and sounds. So, in the lines following the word "flings" (line 13), the "f" sound seems to dominate: "Fann'd by the water-fall! and there my friends." You see other examples of the repetition of sounds elsewhere, such as "winning my way" in line 31 followed by "With sad yet patient soul" in line 32. Other patterns include the frequent use of commas in the middle of lines and the use of single adjectives in front of nouns: "transparent foliage," "fronting elms," "dark branches," and so on.
Finally, the poem uses exclamation marks to note shifts in volume or intensity. The poem begins on such a note, as the speaker gets carried away with pessimistic thoughts about being in prison and going blind. As a general rule, every time he gets started on a description of the natural landscape – especially plants – you can bet that the verses will crescendo in some kind of exclamation. As he moves from specific images (elms, walnut-trees, bats) to abstract ideas (Nature! Love! Beauty! Joy!), the sound of the poem changes to reflect a kind of natural ecstasy. Though "This Lime-Tree Bower My Prison" is often called a "conversation poem," the sound of the poem more accurately reflects celebration than conversation.