Sonnet 106 conforms to the Elizabethan fourteen-line stanzaic form. Each of the lines contains ten syllables, and the poem consists of two sentences. The first encompasses the initial octave, and the second, the final sestet. This form is similar to Shakespeare’s Sonnets 32 and 47. The initial octave may be broken into two distinct quatrains. The first initiates the work with a “when” clause that, while syntactically logical, cannot stand alone.
The second quatrain counters the first with a “then” clause. Through this syntactical convention, logic is used first to divide and then to unite the initial octave. The final sestet similarly depends upon its syntactical sequence first to answer, then to expand upon, the logic conceived in the initial octave. Despite its unification, the sestet is composed of both a distinct quatrain and a concluding couplet.
The quatrain of the sestet begins a new sentence that remarks on the evidence put forward in the preceding sentence. It states that despite the worthy stature of the poets who composed the earlier works, their attempts at prophecy fall short: They were incapable of capturing the beauty of the narrator’s beloved in words. The main point of the work, however, is the narrator’s own seeming inability to put his love’s beauty into words.
The sonnet uses alliteration, particularly of the s sound, throughout the poem. Shakespeare also creates effects by expanding or contracting the number of syllables that appear between certain repeated sounds. In the couplet, for example, a pulsating alliteration emphasizes the poem’s conclusion; the “praise” of line 14 represents a compression of the pr and ay sounds previously heard in the “present days” of line 11. There is also an expanding alliterative pattern in the placement of b and pr sounds. In line 9, the pattern begins with “but prophecies.” The sound is stretched in line 13—“behold the present”—and stretched even further in the final line: “but lack tongues to praise.”
Sonnet 106 exhibits Shakespeare’s uncanny ability to manipulate language into poetic form; the poem is not as simple and straightforward as it may appear. In line 3, the narrator refers to the “beautiful old rhyme” of bygone days, yet he is speaking a poem that both echoes and modifies those old rhymes, a poem that will one day take its place in the canon to which they belong.