Answer

There is alliteration ‘gravelly ground’ with the ‘g’ sound expressing the harsh sound the spade makes as it enters the ground.

His admiration for his skill is shown in the seventh stanza with onomatopoeic words ‘nicking and slicing’ showing the skill of his cutting of the turf precisely.

The early focus of the poem is on writing, where the pen is compared using a simile with a gun, almost as if the pen can do as much damage as a gun, if required. A lot of Heaney’s writing is political, looking at the troubles in Ireland and the use of violence, so there may be a link here.