The first line of "No, Thank You, John" establishes the poem as a dramatic monologue told from the perspective of a female speaker and directed toward a man named "John." The first line also establishes the character of the speaker, as it is a confident, declarative sentence denying her love for John.
The first line ends in a colon, a preview of the variety of punctuation marks incorporated in the poem. A colon often introduces an explanation, list, or example, thereby developing upon ideas established before the colon. Therefore, in line 1, the colon suggests that the next three lines in the quatrain will elaborate or develop on the speaker's refusal of love.
Indeed, the speaker goes on to ask John why he persists in "teas[ing] [her], day by day" with his requests for love. Lines 2-4 are framed as a rhetorical question without a possible rational answer, showing the futility of John's attempts to court the speaker. The word "tease" suggests a playful provocation and is often associated with women being flirtatious. Here, Rossetti subverts expectations by having John, a man, "tease" the speaker, a woman.
John's "teas[ing]" occurs "day by day" and is thus relentless. The repetition of "day" suggests the monotony of John's persistant romantic attentions. Indeed, in line 3, the speaker notes that John "wax[es] a weariness" or speaks on his love until she is "wear[y]" of the subject. The alliteration of the swift and smooth /w/ sounds in the phrase "wax a weariness" suggests the unceasing and unbroken nature of John's pestering.
In the last line of the stanza, the speaker specifies that John "always" uses the words "'do' and 'pray'" to beg her to return his love. The use of direct quotations allows readers to get a glimpse of John's particular speech patterns. Indeed, the words "do" and "pray" evoke a pleading, whining tone, thereby making John's character and personality more vivid.
"No, Thank You, John" is composed of eight quatrains, or four-line stanzas. The stanzas are mostly written in the unstressed-stressed pattern of iambic pentameter, tetrameter, and trimeter (meaning there are either five, four, or three of those iambs per line). Take, for example, the first stanza of the poem which begins with two lines of iambic tetrameter, followed by one line of iambic pentameter, and a last line of iambic trimeter:
I never said I loved you, John:
Why will you tease me, day by day,
And wax a weariness to think upon
With always "do" and "pray"
The iambic meter of the poem remains relatively consistent throughout. Iambic meter, or "rising" meter, most closely resembles everyday speech. Therefore, the meter suits the poem's framing as a dramatic monologue delivered by the speaker to John in real time.