Explain the motif of light versus darkness in Act 1, Scene 5 of Romeo and Juliet.

In act I, scene 5, Romeo first lays eyes on Juliet at the Capulet ball. He sees her as a stunning light, and in contrast, everything else becomes darkness. As he says:

Oh, she doth teach the torches to burn bright!
It seems she hangs upon the cheek of night
Like a rich jewel in an Ethiope’s ear ...

More light, more light!

How does the imagery of light and darkness relate to the figurative language in Act 2 of Romeo and Juliet?

Much of the figurative language used to depict the light and dark is in reference to the blossoming love we see between Romeo and Juliet. We see this most strongly in the balcony scene, Act II, scene ii.

For example, lines 2-3 set this idea into motion when Romeo states:

But, soft! what light through yonder window breaks?
It is the east, and Juliet is the sun.

Romeo compares Juliet to the sun here as though she is illuminating his world and eliminating the dark emptiness he felt in his love for Roseline. The comparison of Juliet to light-bearing celestial bodies (sun, moon, stars, etc.) continues throughout this scene.

Two of the fairest stars in all the heaven,
Having some business, do entreat her eyes
To twinkle in their spheres till they return.
What if her eyes were there, they in her head?
The brightness of her cheek would shame those stars,
As daylight doth a lamp; her eyes in heaven
Would through the airy region stream so bright
That birds would sing and think it were not night.

For Romeo, Juliet is his "bright angel."

Likewise, Juliet enters into this same metaphor, stating:

therefore pardon me,
And not impute this yielding to light love,
Which the dark night hath so discovered.

Later in the scene, even when Juliet is questioning the logic of the emotions she feels it is this same vein of figurative language that brings her back:

It is too rash, too unadvised, too sudden;
Too like the lightning, which doth cease to be
Ere one can say 'It lightens.' Sweet, good night!
This bud of love, by summer's ripening breath,
May prove a beauteous flower when next we meet.

What is the significance of light and dark imagery in Romeo and Juliet?

Light and dark imagery can symbolize many different things in Romeo and Juliet. Literary critic Clifford Leech argues that the contrast between light and dark imagery shows that, since their love is separated by their feuding families, their love is something unnatural, something that cannot fully exist in the world, but rather something that is doomed to failure as expressed by the dark imagery (Leech, "Rome and Juliet: Romeo and Juliet").

Light imagery is especially used to describe Juliet's beauty, showing us that Romeo sees her as more of a celestial being rather than a real person and that his love for her is otherworldly. Light imagery is especially used in the famous balcony scene when Romeo sees Juliet at her window. Romeo makes an analogy between Juliet and the sun, as we see in his lines, "But soft! What light through yonder window breaks? / It is the East, and Juliet is the sun!" (II.ii.2-3). Since the sun stands above the world, the image portrays Juliet, as well as Romeo's love for her, as otherworldly.

However, while their love is described with light imagery, their meetings always take place at night. One reason is that most amorous activity takes place at night. But another reason, as literary critic Leech suggests, is that the darkness they are in is literally crushing and killing their love, just like their families' feud. As Leech states, "Their love cannot--which is the mark of its doom--exist in the sun, its natural element," which Romeo shows in is paradoxical line, "More light and light; more dark and dark our woes," which he utters just as dawn is breaking the morning after their secret wedding night (Leech, "Rome and Juliet: Romeo and Juliet"; III.v.36).

Hence we see that the light and dark imagery can portray beauty, their love, and also the struggles they are enduring due to their families' hatred.

How does Shakespeare use the motif of darkness in Romeo and Juliet?

For purposes of discussion, the following response to the posted question -- how did William Shakespeare use the motif of darkness in his play Romeo and Juliet -- assumes that the question is multiple choice. If the student's intent is otherwise, then perhaps he or she can repost the question in a clearer manner.

Darkness has served to emphasize underlying themes in the arts for thousands of years. It can suggest foreboding, depression, terror, and any other negative emotion the author/painter/film director hopes to emphasize. In general, lightness equals enlightenment, joy, and optimism; darkness equals the opposite. In the case of Shakespeare's play, the use of darkness highlights the emotional transformations that affect the titular characters throughout. That Shakespeare adroitly used the contrast of light and darkness to emphasize emotions and establish tone. The negative connotations of darkness are employed in the service of a play intended as a tragedy, evident in the fact that the full title of the play is, in fact, The Tragedy of Romeo and Juliet, not simply Romeo and Juliet.

In Act I, Scene II, Capulet, leader of the clan that bears his name and Juliet's father, discusses his arrangement for his daughter to marry Paris, suggesting in their conversation that such a union will illuminate an otherwise bleak environment: "At my poor house look to behold this night Earth-treading stars that make dark heaven light." Later, in Act III, Scene V, Romeo stands beneath Juliet's balcony. These two young lovers, their fates predetermined by forces beyond their control, lament the predicament in which they exist. As Juliet, fearing discovery, urges Romeo depart before he is spotted, Romeo equates their imminent separation with darkness: 

Juliet: O, now, begone. More light and light it grows.
Romeo: More light and light; more dark and dark our woes.

In responding to the student's question, therefore, one must conclude that Shakespeare employed darkness as a means of conveying or emphasizing sorrow and fear, especially the former. 

How does Shakespeare use light and dark imagery in Romeo and Juliet?

One place in which images of light and darkness are merged is in the famous balcony scene. In particular, images of the sun are used as images of light, while images of nighttime, like the moon, are used as images of darkness. Shakespeare uses the images of light and darkness for several reasons. One reason is to symbolize the sexuality that is a dominant theme.

Romeo's feelings of sexual attraction for Juliet are especially expressed using light and dark images in his opening soliloquy in Act 2, Scene 2. He compares Juliet to the sun in order to capture her beauty, as we see in his lines, "What light through yonder window breaks? / It is the East, and Juliet is the sun!" (2-3). Since the sun is the brightest object in the sky, comparing her to the sun describes her beauty as being glorious and bright, just like the sun.

More importantly, he also uses nighttime imagery to express his sexual desires for Juliet. He uses an extended metaphor likening Juliet to the moon's handmaiden, telling her in his mind to kill the moon and cease being her handmaiden. The moon literally refers to the Roman goddess Diana, goddess of the moon and childbirth who is especially known for her vow of chastity. Hence, when he tells her in his mind to cease being the moon's handmaiden, he is really telling her to give up her chastity, which we especially see in his lines, "[the moon's] vestal livery is but sick and green, And none but fools do wear it. Cast it off" (8-9). Since vestal livery can be translated as virginal uniform or clothing, Romeo is metaphorically in his mind telling Juliet to cast off her clothing. The nighttime imagery is especially significant because it is typically at nighttime when sexual activity takes place. Hence these two images of light and darkness combine to paint a provocative picture of Shakespeare's ongoing sexual theme.