Let us start with analyzing the poem's basic structure. The poem is comprised of four stanzas. Each stanza is six lines long, which is a sextain in poetry language. What is unique about each sextain is that each one contains a tercet. A tercet is a set of three lines. The lines do not have to always rhyme, but Wyatt makes his tercet stand out within each stanza by having the same rhyme:

That hath given thee my heart
Never for to depart,
Nother for pain nor smart;

And is / thy heart / so strong

Thomas Wyatt's poem "And Wilt Thou Leave Me Thus" isn't written in the sonnet form of fourteen lines with an ending couplet. Instead, it has four sextain stanzas (six lines each), each beginning with "And wilt thou leave me thus?" and ending with a repitition of "And wilt thou leave me thus?" followed by the pleading "Say nay, say nay!" Stanza two has the variation "As for to leave me thus?" The rhyme scheme is abbba, followed by "Say nay! Say nay!"

Wyatt wrote this impassioned poem as a plea to his mistress not to leave him after all the years they had been together. In it, he pleads with her to say "no" out of the shame of causing him grief and sorrow after all the years that he loved in "wealth and woe" and never faltered through "pain nor smart."