Frost's poem is tightly constructed, imbued with multiple layers of meaning, and thematically important in its treatment of both the individual and the environment.
From the first line, we see Frost's deft touch: "Whose woods are these, I think I know." We have the alliteration of whose and woods, these and think, I and I. We also know that the place he wanders through is familiar, but that he is probably a trespasser.
Notice how the word "woods" is repeated four times. Each time "woods" appears, one senses the speaker's isolation, both physically and spiritually. The woods separate the speaker from humans and place him within the coldness of the natural world: "Whose woods are these I think I know / His house is in the village though"; the woods "fill up with snow" and are on a "frozen lake"; the woods are "lovely, dark, and deep."
The natural world may be harsh but the speaker finds beauty there as well. For example, the snow that falls is given the beautiful description of "downy flakes." The woods, though cold and frozen, are also "lovely."
The use of figurative language is another device Frost uses. We do not know what "promises" the speaker has made, but the twice repeated "miles to go before I sleep" may mean that it is a long time before the man will die and that there is much to do before his time on earth comes to an end.
The use of iambic pentameter is one device that makes the poem wonderfully readable. In this poem, Frost uses iambic pentameter, which is when you have an unstressed syllable followed by a stressed one. For example, if I copy a few of Frost's lines from the poem here and then capitalize the part of the word that the stress is on, you will be able to see iambic pentameter more clearly:
Whose WOODS are THESE I THINK I KNOW
His HOUSE is IN the VILLAGE, though; (qtd. in Enotes)
Also, Frost's diction is fantastic. Diction is a writer's choice of words he/she uses. Frost's diction sets the tone of this poem, which is one of melancholy and quiet reflection.
While some believe that the poem is written in iambic pentameter, in reality it is iambic tetrameter. There are four feet per line:
Whose WOODS are THESE i THINK i KNOW.
The poem also uses alliteration quite effectively. "H" is an important repetitive sound that appears in whose, house, here, and his. Another letter used for alliteration is "W." This sound is present in woods, will, and watch.
The addition of the refrain at the end of the poem adds depth to its meaning: And miles to go before I sleep,/ And miles to go before I sleep. Like a song fades out, the poem, this brief respite, also fades away and the narrator must re-enter the reality that is his life. As much as he would like to continue to enjoy the beautiful view of the snow falling into the woods, he is pulled back to social responsibilities that he dreams of neglecting.
frost wrote the poem using nature,like snow, woods etc