Regarding Robert Frost's two poems, "Birches" and "Stopping by a Woods on a Snowy Evening," perhaps you could compare and contrast the speaker's involvement with nature as he observes it.
For instance, in "Stopping by a Woods on a Snowy Evening," the speaker's main desire is to contemplate the beauty of nature, to take a respite from his obligations--"I have promises to keep"--and simply revel in the peace and beauty of the woods. However, in "Birches," the speaker does not approach the observation of the trees from an aesthetic perspective; instead, he is more analytical. The pliable quality of the birches--"I like to think some boy's been swinging them"--initiates an involved meditation on the part of the speaker. Unlike the contemplation of nature in the other poem, the speaker's contemplation is the appreciation of the beauty of the birches is not the final thing that interests the speaker; rather it is the strange association of the trees with his reasoning that is most central to "Birches." The tension between what has actually happened and what the poet would like to have happened is central to this poem. Thus, the lines
We may as well go patiently on with our life
And look elsewhere than to stars and moon and sun
For the shocks and changes we need to keep us sane
while ostensibly similar to the refrain "I have promises to keep" have a much different implication.
Be sure to check out the sites below which will assist you in more interpretation. And, do not forget that in comparing and contrasting poems, one always should examine how poetic devices are employed in each poem.
How about 'The Significance Of The Symbolism Of Trees In The Poetry Of Robert Frost?' Both the poem 'Birches' and the poem 'Stopping By Woods On A Snowy Evening' deal with trees, nature and growth and landscape in different ways. In 'Birches' the poet examines youth, growth and the resilience and suppleness of young growth (involving branches, saplings and the idea of transference of weight.) The other poem deals with trees in a group - how, huddled together and growing as a group they aid the snow in blanketing and silencing the earth. Yet the forest they have become is inviting, calling passers by to draw into the silence now underlined by the muffling snow. The idea is one of peaceful,yet unthreatening, alone-ness.