In Romeo and Juliet, how would you characterize Romeo while using three examples to back up this characterization?
I would characterise Romeo as a very modern lovestruck teenager. First of all, like nearly all male teenagers, he's self-conscious and awkward:
Not I, believe me. You have dancing shoes
With nimble soles; I have a soul of lead
So stakes me to the ground I cannot move.
Juliet even asks later "who's that... that would not dance?". Romeo's too self-conscious to dance at the party!
Secondly, it's important to say that he's extremely impetuous, and acts based on his feelings. One minute he's moody about Rosaline, and then, the next, as Friar Laurence points out, he's in love with Juliet:
Is Rosaline, that thou didst love so dear,
So soon forsaken? Young men's love then lies
Not truly in their hearts, but in their eyes.
Lastly, I'd characterise Romeo as someone who feels extremely deeply and who has capacity for tremendously heightened, lifting language. He is imagining Juliet's eyes being stars in heaven:
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.
Hope it helps!