“Digging” features a series of end rhymes in the opening stanzas, but then all but abandons rhyme for the rest of the poem. The first five lines follow a clear AABBB scheme:

Between my finger and my thumb 

The squat pen rests; snug as a gun.

 

Under my window, a clean rasping sound 

When the spade sinks into gravelly ground

My father, digging. I look down.

Admittedly, the first rhyme pair—“thumb” and “gun”—forms a slant rhyme, meaning that the sounds don’t match up perfectly. However, the final “m” and “n” sounds are close enough to approximate an exact rhyme. A similar phenomenon happens in the set of rhymes that follows. The words “sound” and “ground” form an exact rhyme, and “down,” though technically slant because it lacks a final D, nonetheless sounds close enough to be a perfect match. These rhymes set up an expectation for further rhyme that Heaney undercuts in the following stanza, which features the following four end words: “flowerbeds” (line 6), “away” (7), “drills” (8), and “digging” (9). For the rest of the poem, the only rhymes that appear are slant, and these slant rhymes are much less exact that those in the opening stanzas. For example: “hands” and “man” (lines 14 and 16), and “spade” and “day” (lines 15 and 17).

The abrupt abandonment of rhyme in the poem is significant, particularly when we recall that “Digging” marked the symbolic opening of Heaney’s career as a poet. Indeed, the poem served as the opening to his debut collection, The Death of a Naturalist (1966). By starting the poem with a series of rhymes, it’s almost as though Heaney briefly adopts the traditional elements of poetry, only to relinquish them as he attempts to forge his own path as a poet. In this regard, Heaney’s use of rhyme echoes the action of the poem’s speaker, who looks back on the traditions established by his father and grandfather. While the speaker uses his verse to honor these traditions and the men who formed them, he also respectfully parts ways from those traditions. Instead of pursuing a life of manual labor, he has chosen to stake out a new path for himself through the craft of writing. Hence, the partial use of rhyme in the poem serves as a symbolic gesture of respect to a tradition that the poet ultimately doesn’t take up.