‘Mending Wall’ is a 1914 poem by the American poet Robert Frost (1874-1963). Although it’s one of his most popular, it is also one of his most widely misunderstood – and, like another of his widely anthologised poems, ‘The Road Not Taken’, its most famous lines are often misinterpreted. Before we address these issues of interpretation and analysis, it might be worth reading ‘Mending Wall’ here.
To summarise: ‘Mending Wall’ is a poem about two neighbours coming together each spring to mend the wall that separates their two properties. This wall is made of stones piled on top of each other, and the winter weather has ravaged the wall and left it needing repairs, because there are gaps in the wall between stones. Hunters coming past have also knocked holes in the wall. The speaker of the poem (this poem is a lyric, expressing the personal thoughts and feelings of the poem’s speaker, although whether the speaker and Frost are one and the same is difficult to say; there’s almost certainly some overlap here, though) approaches the chore of mending the wall as a sort of game.
While he and his neighbour fix the wall, it becomes clear that the speaker isn’t convinced by the need for a fence dividing their two properties. When he asks his neighbour what the purposes of the dividing wall is, all his neighbour can do is parrot an old piece of wisdom his father used to say: ‘Good fences make good neighbours.’ We might interpret this piece of family wisdom as meaning: having clear boundaries between ourselves and others leads to healthy relationships between neighbours because they won’t fall out over petty territorial disputes or ‘invading each other’s space’. For instance, we may like our neighbours, but we don’t want to wake up and draw the 
curtains to find them dancing naked on our front lawn. There are limits. Respecting each other’s boundaries helps to keep things civil and amicable. However, does this mean that Frost himself approves of such a notion?
‘Mending Wall’ is frequently misinterpreted, as Frost himself observed in 1962, shortly before his death. ‘People are frequently misunderstanding it or misinterpreting it.’ But he went on to remark, ‘The secret of what it means I keep.’ Which, let’s face it, doesn’t exactly clear up the matter.
However, we can analyse ‘Mending Wall’ as a poem contrasting two approaches to life and human relationships: the approach embodied by Frost himself in the poem (or by the speaker of his poem, at least), and the approach represented by his neighbour. It is Frost’s neighbour, rather than Frost himself (or Frost’s speaker), who insists: ‘Good fences make good neighbours.’
‘Good fences make good neighbours’ has become like another of Frost’s sentiments: ‘Two roads diverged in a wood, and I, / I took the one less travelled by.’ This statement, from ‘The Road Not Taken’, is often misinterpreted because readers assume Frost is proudly asserting his individualism, whereas in fact, as we’ve discussed here, the lines are filled with regret over ‘what might have been’.
‘Good fences make good neighbours’ is actually more straightforward: people misinterpret the meaning of this line because they misattribute the statement to Frost himself, rather than to the neighbour with whom he (or his speaker) disagrees. As the first line of the poem has it, ‘Something there is that doesn’t love a wall’: this, spoken by Frost or by his poem’s speaker, clearly indicates that Frost does not agree with the view that ‘good fences make [for] good neighbours’.
‘Mending Wall’ is written in blank verse, which is unrhymed iambic pentameter. Given the closeness of iambic pentameter to ordinary human speech patterns in the English language, and the more natural tone which the lack of rhyme helps to create, this is a particularly pertinent choice of verse form for a poem about two neighbours chatting (although before we overinterpret the significance of the blank verse for ‘Mending Wall’, it’s worth mentioning that Frost uses this verse form in many of his poems).
However, it’s worth stopping to consider the conversational nature of the speaker’s account of mending the wall, and the significance of the two men’s utterances in ‘Mending Wall’. Whereas the speaker of the poem is explorative, playful, ironic, and even tongue-in-cheek (for instance, pretending that they have to cast a spell to keep some stones in place), his neighbour can only repeat the same mantra whenever the speaker asks him what the purpose of the wall is: ‘Good fences make good neighbours.’ This is taken as sufficient. In other words, it’s as if the neighbour is putting up a metaphorical ‘wall’ between him and his neighbour, refusing to share in his more relaxed and puckish attitude towards the question of the wall. For the neighbour, the hand-me-down proverb from his father is enough wisdom for him to live by: it’s always been said, as far as he’s concerned, that ‘good fences make good neighbours’, so who is he to question such a notion? By contrast, Frost’s speaker can’t resist questioning or probing the matter.
In this connection, Frost’s line, ‘We keep the wall between us as we go’ can be taken as double-edged: physically they keep to their own sides of the wall, respecting the physical boundaries between their homes, but there’s also a figurative suggestion of putting up social boundaries between them and not being entirely honest or open. Yet it’s also worth acknowledging, as a final point of analysis, that through ‘mending wall’ so as to retain it, the speaker and his neighbour also come together: the wall brings them together as they ‘meet’ in order to mend it, but they only come together in order to reinforce the division between them.