We might not be able to supply you with the specific name of the speaker in "Lines Written in Early Spring ." We can't tell you that the speaker is Tom Beverly (someone we just made up) or Rachel O'Connor (another person we just made up), but we can...
We might not be able to supply you with the specific name of the speaker in "Lines Written in Early Spring." We can't tell you that the speaker is Tom Beverly (someone we just made up) or Rachel O'Connor (another person we just made up), but we can find evidence about who this person might be.
Think about where this person is. They’re in a "grove" or an orchard. They’re with nature. What does nature do to their mood? It puts them in a "sweet mood." We could say that our speaker is a person who likes nature.
As the poem moves along, we come across further evidence that our speaker has a passion for nature. The speaker tells us how they enjoy the "pleasure" of the "budding twigs" and "breezy air."
What doesn't the speaker seem to enjoy? The current state of human beings. The joy of nature makes our speaker "grieved" about "what man has made of man." Perhaps our speaker is a bit misanthropic. Juxtaposing humans—or "man"—with nature makes us think that our speaker is someone who believes that humans in general have become too separated from nature. These humans don’t appreciate it enough.
Unlike the unnamed human who narrates this poem, we get the idea that general humans don't tend to sit in a grove and gaze on the "fair works" of nature. We could probably safely conclude that one of those general humans is not our speaker.
Of course, William Wordsworth, the author of the poem, was a noted Romantic. He adored nature and was anxious about the increasing separation between humans and nature. Perhaps our narrator is not as nameless as we've made them out to be. Perhaps our narrator is William Wordsworth himself.