stops on horseback to spend a few moments watching a beautiful snowfall in the woods, struck by the beauty of the feathery white snowflakes against the black sky. He regrets that he has

promises to keep,
And miles to go before I sleep

However, he does not regret taking the time out to watch the "lovely" scene.

Both speakers note the loveliness of the scene before them and its fleeting quality. Both use simple words, yet they convey a sense of longing and regret that there is not more time to appreciate nature's bounty, which can be easy to miss in the rush of life. I personally love both poems because the speakers are able to communicate sensitivity to, and yearning for, loveliness, without self-pity or "woe is me" antics. They simply and movingly capture how ephemeral and fragile life's most beautiful moments are.

A theme is a universal truth that a reader can glean from a piece of literature. Two poems that have similar themes are "Casabianca" by Felicia Dorothea Hemans and "The Charge of the Light Brigade" by Alfred, Lord Tennyson. Both poems focus on the subject of a subordinate who follows orders during a military confrontation even though the orders are not well conceived and will result in the subordinate's death. 

In "Casabianca," the hero of the poem is a young boy whose father has commanded him to remain on the deck of the ship. Although the ship is under attack, the boy will not move from the place his father has told him to stand. He calls for his father to obtain permission to move, but since he hears no reply, he remains and perishes with the ship. It turns out that his father is incapacitated below and unable to respond to his son's cries. Readers cannot help but wish that the father had given his son more complete orders that would have allowed him to save himself if he was unable to gain a reply from his father. 

In "The Charge of the Light Brigade," Tennyson writes of a battle during the Crimean War when a commanding officer gave a mistaken order that sent the British cavalry into a death trap with cannons on three sides as they rode into "the Valley of Death." The majority of the six hundred horsemen perished as a result. Tennyson acknowledges the fact that "someone had blundered." In fact, the orders had gotten confused.

In both poems, the poet chooses to focus on the valor of the subordinates rather than on the foolishness of the superiors who did not act with the welfare of those under them in mind. Hemans writes that "the noblest thing which perished there was that young faithful heart." Likewise, Tennyson praises the horsemen, calling on readers to "Honor the charge they made! Honor the Light Brigade! Noble six hundred!"

Thus both poems share the theme that in a military conflict, those who perish while obeying orders, even if those orders are mistaken, deserve high praise and honor. 

The poems "Do Not Go Gentle Into That Good Night" by Dylan Thomas and "Annabel Lee" by Edgar Allen Poe share themes of death, love, and confronting loss. 

Your teacher will almost definitely want to prove that (a) each poem features these themes and that (b) the poems are similar in their representation of the themes. To do so, here are my suggestions: 

1. You know what themes you are looking for. Go through each poem and find 3-5 quotations that you think display one or more of these themes. 
2. For each quotation, explain exactly why/how the theme is present in the quotation. It's not enough to just say that it's there - what makes it there? Is it in the imagery? The figurative language? The tone? Try and be as specific as possible. 
3. Write 1-2 lines about how/why these poems are similar. Don't just say that they share these themes! Explain what about these themes makes them resemble each other. 

In my opinion, the easiest way to tackle this question would be look at a simple theme like love. I will introduce three of my favorite love poems to give you an idea of how to answer this question. The poems are:

• "[i carry your heart with me(i carry it in]" by e. e. cummings
• "To My Dear and Loving Husband" by Anne Bradstreet
• "Mad Girl's Love Song" by Sylvia Plath

It is worth noting upfront that poets like Shakespeare, Lord Byron, and Elizabeth Barrett Browning also offer wonderful examples of love poems that you could analyze.

Cummings arguably has one of the most unique styles of poetry in the English language. He expresses his love by explaining that he is never without his beloved because he carries her heart with him everywhere, and that everything he achieves are actually her achievements. This implies that she is so much a part of him that he is nothing without her. His love extends to calling his lover his "fate" and his "world."

Anne Bradstreet's "To My Dear and Loving Husband" takes on a far more conventional style of poetry. This poem talks about how happy she is in her marriage and how much her husband means to her. The fact that this is a love poem is apparent throughout, and she describes her love as something that cannot be quenched even by an entire river. The theme of love is emphasized in the previous line, where she declares that she values her husband's love "more than whole mines of gold."

A third poem that deals with the theme of love—albeit differently—is Sylvia Plath's "Mad Girl's Love Song." While also touching on mental illness issues, Plath's poem speaks directly to the speaker's former lover. The reader is left in no doubt as to the intensity of the speaker's feelings:

I dreamed that you bewitched me into bed
And sung me moon-struck, kissed me quite insane.
(I think I made you up inside my head.)

While this poem deals with a love that has been lost, rather than a love that burns on, love is a prevalent theme.

Cummings, Bradstreet, and Plath all have different ways of expressing their opinions of love, but there can be no doubt that these three poems deal with a similar theme.