The first four lines of “The Passionate Shepherd” establish the poem’s broad subject and its approach to this subject. The speaker begins by directly addressing someone, whom he refers to simply as his “love,” without specifying the person's gender. The entire poem will be addressed to this "love." This is an instance of apostrophe. It makes the poem feel intimate and direct: the speaker is not addressing a broad, general audience. Rather, he is trying to convince someone of something specific: he is trying to seduce the person he addresses, to convince his "love" to follow him to the countryside. The speaker’s language here subtly suggests some differences between himself and his “love.” While the speaker is, as the poem’s title suggests, a “shepherd,” someone who works with sheep and lives in the country, his “love” is not. This person has to be convinced to "come" to the country—which implies that they do not live there already.
The poem’s second line suggests how the speaker will try to seduce his “love.” Once they are in the country together, they will try “all the pleasures”—every delight and joy offered in rural settings (the speaker goes on to list those many settings in lines 3-4). Right away, the speaker depicts the countryside as a pleasurable space: he does not mention the downsides of living in the country, or the difficulty of working on a farm or with livestock. It's clear from line 2 that his portrayal of life in the country will be idyllic and idealized—perhaps too much so.
As if to underline this focus on pleasure, the writing itself—here and throughout the poem—is unusually musical and rich in sound. The poem begins with a strong alliteration on the /l/ sound in the first line: “Come live with me and be my love.” (This line will eventually become a kind of refrain for the poem, recurring in lines 20 and 24). This /l/ sound is carried through the next several lines, becoming consonance as it continues: “And we will all the pleasures prove…” Although these lines are wide-ranging in content (particularly lines 3-4), they are knitted together by this unifying sound.
These lines are further organized formally: each line is in an easy iambic tetrameter; the quatrain is divided into two rhyming couplets, with strong end-rhymes. Later in the poem a clear pattern of enjambment and end-stop will develop, alternating line by line between the two. But here that pattern has not yet developed; while lines 1 and 4 are end-stopped, lines 2 and 3 enjambed. There is thus a tension between the rhyming couplets, which serve as sonic units, and the grammar of the quatrain, which crosses the boundaries of those couplets. This gives the poem, right from the start, a sense of looseness: though it has underlying formal architecture, it is not fussy or overly precise. Instead, in its informality, it imitates the easy-going country life it describes.