In the first stanza, Byron uses a metaphor when he refers to himself as "broken-hearted." His heart of course is not literally broken, but the metaphor here helps to convey how mournful and disconsolate he feels.

There is also repetition in the first stanza. The speaker says that his lover's kiss grew "cold, / Colder." The repetition here emphasizes the point that the passion seemed to drain from the relationship.

In the first stanza, there is also enjambment, whereby one sentence will continue across two lines. For example, the first line, "When we two parted," continues on to the second line with "In silence and tears." The enjambment here creates a pause between the two clauses, and the pause suggests perhaps a sigh. It is as if the speaker is reluctant to remember the "silence and tears" which marked his parting from his lover.

In the second stanza, Byron continues with the motif of coldness. He refers to the "dew of the morning" and the "chill on (his) brow." The recurring motif of coldness emphasizes the point that the relationship became drained of life and passion but also indicates that the speaker, after the relationship ended, felt emotionally cold and drained himself.

In stanza three, Byron uses a rhetorical question when he asks, "Why wert thou so dear?" The rhetorical question here implies that the speaker is perhaps upset with himself that he ever allowed himself to fall in love so completely with the woman who betrayed him.

Also in stanza three, Byron also uses aural imagery when he refers to the "knell" which he hears every time he hears his former lover's name. The word "knell" describes the low, mournful sound that a bell makes when rung to announce a death or at a funeral. The implication is that whenever he hears his former lover's name he is reminded of the death of their relationship. Whenever he hears his former lover's name, he also perhaps feels as if he is experiencing that death again.

In the fourth and final stanza, Byron creates a circular narrative when he concludes the poem with the phrase, "silence and tears." This phrase is also used in the second line of the poem. The poem beginning and ending with this phrase suggests that the speaker cannot escape the silence or the tears consequent of his separation from his former lover. The repetition of the word "silence" emphasizes how lonely he feels after the separation, and the repetition of the word "tears" implies how endlessly sad he is.

Like all poetry, “When We Two Parted” by Lord George Gordon Byron contains figurative language and other devices which serve to enhance the meaning of the poem. This is a poem in which the speaker is broken-hearted because his love has walked away, so we would expect the language he uses (the language of the poem) to reflect the pain of his loss.

The poem is replete with sensory imagery, words and phrases that appeal to the senses. Sound imagery includes noises we can hear, such as weeping, speaking, and the ringing of a death bell (“A knell to mine ear”); it also includes silence. All of these are sounds associated more with death and loss than with happiness and love, which is apt for this poem. Sight imagery includes a rosy cheek growing pale; a kiss, dew, and a shudder are all examples of touch imagery.

A metaphor compares two unlike things, and here Byron compares hearing his former lover’s name to the ringing of a bell:

They name thee before me,

A knell to mine ear….

The implication here is that, now that his love has left him, hearing her name is like a death knell, a bell which tolls when someone dies. Figuratively, of course, this woman has died to him.

Alliteration is also used to add emphasis to the speaker’s loss. Note the use of the harsh “K” sound in the following lines:  

Pale grew thy cheek and cold,

Colder thy kiss….

Rather than the soft, rounded, mellifluous sounds one might expect from someone in love, these harsh sounds are indicative of a cruel, abrupt breaking. This is a perfect example of sound and sense combining to both form and enhance meaning.

In the next stanza, the speaker suggests that his former lady love has ruined her reputation. Her word means nothing, her vows are now worthless, and her reputation is “light.” The alliteration we hear next is perfect to express the fact that the speaker now feels as if her shame is his.

Thy vows are all broken,

And light is thy fame;

I hear thy name spoken,

And share in its shame.

Sharing shame is something he would rather not do, thus the sound: shhhhhh. 

Just a note in terms of meter (line length). Notice that the first stanza has the shortest lines in the poem--which makes sense, since this is the stanza in which the woman's love dies (grows "cold, [c]older"). What happens after that is a little more expansive, so the lines are a few syllables longer in the next two stanzas. In the last stanza, when the speaker reviews his grief and contemplates his future, the lines shorten again. 

Finally, the repetition of the phrase "silence and tears" is a striking image with which the speaker begins and ends this poem. The opening stanza talks about the lovers' parting, and there is silence (undoubtedly from her, as she grew "cold" and "colder") and tears (undoubtedly from him). In the closing stanza, the speaker explains that they met in secret, implying their affair was illicit; the woman was not available, but she loved the speaker anyway. Now he grieves in silence because her heart has forgotten him and her spirit has deceived him. If, by chance, he ever meets her again, he plans to greet her the same way they parted, with "silence and tears."

Poetry is more than just the meaning of the written words; the use of language and other poetic devices evoke emotions beyond the words. This blend of sound and sense is what helps the reader feel what the speaker feels. In this poem, we feel his heartbreak and loss.