"I Wandered Lonely as a Cloud" employs various literary devices to demonstrate that experiences in nature provide deep and meaningful joy which can alleviate feelings of melancholy.

The poem opens with a simile: "I wandered lonely as a cloud." This conveys that the speaker feels separate from his world. He floats aimlessly and without a sense of purpose. This is also an example of anthropomorphism, which is giving a human emotion to a nonhuman object.

There is a regular rhythm to this poem. It is written in iambic tetrameter, which suggests a steady walking pace, reflective of the speaker's trek to this lake. The poem also has a predictable rhyme pattern, which conveys the certain assurance that nature provides in his life.

There are several examples of alliteration. One example is at the end of the second stanza: "Tossing their heads in sprightly dance." The whistling repetition of the s sound is a reminder of the breeze which blows and moves these daffodils.

The poem also employs caesura, demonstrated in this line: "I gazed—and gazed—but little thought." This intentional pause within the line reflects the speaker's efforts to appreciate the beauty before him. This requires his own intentional pause and a commitment to focusing on this scene, much as the reader must slow down and commit to this line for longer than would be necessary without the em dashes.

When the speaker concludes that this thinking back upon this scene of daffodils brings joy to his "heart," he is employing metonymy. Of course, his coronary system is not literally affected by this memory, but his spirit of joy is. We often consider a person's heart to represent his soul or emotional well-being, and that is how the speaker is employing the term heart here.

An overarching figure of speech that Wordsworth uses in his poem "I Wandered Lonely as a Cloud" is meter. The poem is written in four stanzas, each consisting of six lines of iambic tetrameter rhymed ABABCC.

He also uses the figure of isocolon, parallel clauses each of the same length and rhythmical pattern in the line:

Beside the lake, beneath the trees ...

The poem begins with a simile, a figure of explicit comparison, when the narrator says he was as "lonely as a cloud." A second figure of comparison, metaphor, which does not use explicit comparative terms such as "like" and "as", can be found in the comparison of the daffodils with the stars in the galaxy. In his numbering them as ten thousand, he uses the figure of hyperbole or exaggeration. 

Wordsworth personifies the daffodils, describing them as if they were human capable of human feelings and actions such as dancing and jocundity.

In the first line Wordsworth uses personification and simile: 'I wandered lonely as a cloud'. A cloud can obviously not wander or feel lonely - these are human attributes or actions. The comparison effectively reflects the Romantic ideal of finding expression for the human condition in nature and establishes the link between man and nature. Furthermore, the line also expresses the idea of the poet or artist finding inspiration when he/she is isolated from the rest of mankind and is at one with nature - another Romanticist aspiration.

'Crowd' (line 3) and 'fluttering and dancing' (line 5) extend the personification. A large number of the daffodils seem to be dancing, celebrating their freedom and being in nature (natural).

The infinite beauty of the flowers and their link with what is natural is emphasized in the second stanza through the simile: 'Continuous as the stars that shine and twinkle on the milky way'. 'Tossing their heads in sprightly dance' is once again, personification, again emphasising the joy of nature.

Stanza three further extends the personification with the waves also dancing, but the daffodils joyously outdances them. Wordsworth says that their company is 'jocund' - they are full of joy and life. The metaphor emphasizes the joy nature can bring, for the speaker declares that he 'little thought what wealth the show to me had brought'. He was enriched by the experience without even realising it at the time.

The value of the experience lies within the speaker's memory. So charmed was he by witnessing these beautiful daffodils that 'my heart with pleasure fills and dances with the daffodils', whenever he is in deep thought and recalls the experience.

There are a number of figures of speech in this poem.

The first is personification: "I" and "cloud" are being personified. The second is the simile "as a cloud." The daffodils are also personified as they dance and are gleeful.

Tossing their heads in sprightly dance.
The waves beside them danced; but they
Out-did the sparkling waves in glee:

The waves are also personified as they dance. That should get you started on your essay. This poem is about a moment in time when Wordsworth and his sister were walking along the lake shore in Cumbria County, England 1802. The theme is about how nature's beauty is often unappreciated or undervalued.