Romeo is sad and lonely. His father has seen him with 'tears', and Romeo stays in his bedroom on his own. Also when Rosalind leaves him he is heartbroken and Rosalind want to go to a nunnery and doesn't want to marry anyone. Romeo says 'O, she is rich in beauty, only poor, That when she dies with beauty dies'. Romeo is puzzled in why she would waste her beauty and why she keeping a promise of her being a nun instead of being with him.
Romeo fears for the future. Before the ball he talks about something 'hanging in the stars' (as if he realises fate will destroy his future). This is foreshadowing that Romeo will die and dramatic irony is used as the audience, we know from the prologue Romeo and Juliet die.
He falls instantly in love as he asks 'Call me but love, and i'll be new baptised'. Also he falls in love by just looking at her and it's not true love.
He tries to do the right thing as he refuses to fight Tybalt, even if he seems a coward due to Tybalt and him being related after the wedding between him and Juliet. Romeo says 'I do protest, I never injured thee'.This shows he will never fight anyone and he is against injuring humans.
Romeo can be immature and even the nurse tells him to stand up and 'be a man'. He is immature probably due to his age and he's on 16 (teenager), and this age is young meaning he's not very immature.
He will not listen to reason. He says, 'I defy you, stars!', as if he does not care what will happen.He is passionate about Juliet as he kills himself in order to be with her.