Something There Is That Doesn't Love A Wall Meaning
In "Mending Wall," what does the first line mean: "Something there is that doesnt love a wall that sends the frozen-ground-swell under it."
The fact that the speaker does not specify what, precisely, is the "Something" that "sends the frozen-ground-swell" under the fence could mean that the word something refers to nature, as another educator suggested, or even God. The word "sends" in line two implies that the sender has a will, a conscious purpose, so it seems logical to consider the possibility we should attribute such a sending to a higher being. Further, in the lines which follow the first two, this "Something" also "spills" the big rocks from the top of the fence out into the sun and "makes gaps" in the fence where two grown men can walk through, side by side (lines 3, 4). These verbs are also active, like "sends," and imply reason and purpose to the one who performs the actions. Therefore, it is plausible that the "Something" which sends "the frozen-ground-swell"—freezing the water in the ground so that the ground literally swells and bursts the fence with the movement—"spills boulders," and "makes gaps" refers to God.
In the poem "Mending Wall" by Robert Frost, we also get the impression that the author is talking about subjects other than Nature alone. With the words "Something there is..." he may be saying that the something is something in human nature that doesn't like or need walls either, something that doesn't like or see a need for barriers or conventions or restricitions all the time. Robert Frost could be talking about himself here too. Yes, he goes on to say - lots of people do believe that good fences make good neighbours because no-one then bothers or encroaches upon anyone else. But others (Frost himself?) believe that there is no need,for example, to protect cattle from apple trees, or corn from forestry plantations. He is saying that some people use protection as an excuse for peoperty delineation and staking claims. Think of the Berlin Wall/Great wall too.
Literally, what this means is that (the speaker says) nature does not like walls. He is saying that nature does not like to be hemmed in.
Because nature does not like walls, he says, it tries to break them down. The frozen ground swell is probably what is called a frost heave. It's a thing where ground (water in the ground, actually) freezes and thaws and swells up because of that. If it does that under a fence, it can break the fence. You can see it happen to roads in places that have the right climate.