Sarcastic, Lonely, Fair
At first, Beatrice didn't want to get married. She left Benedick when they were dating because she was afraid he would leave her, causing her to be humiliated and look like a fool. He was considered a player and Beatrice did not wish to be just another pawn in his games. So she left before he could break her heart and make her look like an idiot. Every time after that, any time Beatrice were to see Benedick, she would insult him and didn't let things go. She is motivated by the constant bickering between herself and Benedick to remind her not to fall in love again.
"I had rather hear my dog bark at a crow than a man swear he loves me."
In the beginning, Beatrice despises Benedick and wanted nothing to do with him. Anytime she saw him, she would insult him and act like he was the most foul creature she'd ever met. Later on in the book, she is tricked by her cousin into overhearing her say to two gentlewomen, Margaret and Ursula, that Benedick never stopped liking Beatrice and was practically head over heels for her. Her perspective of him then changes and she finally lets go of most of her feelings of hatred towards him, allowing her the chance to think about her own true feelings for him, and to think about the fact that she also never truly stopped liking Benedick.
"You have stayed me in a happy hour. I was about to protest I loved you."
Beatrice impacts the plot in many ways. After her cousin, Hero, was wrongfully accused, Beatrice stands by Hero's side and protests that her cousin would never have done any of the things she was accused for. Beatrice gets very upset and after everyone leaves, she stays behind and Benedick comes to her side. Beatrice tells him that if he loves her, he will go and kill Claudio for destroying Hero's reputation and breaking her heart. If Beatrice hadn't been in the story, no one would have stood by Hero and Benedick would not have challenged Claudio, nor would Benedick have gotten married at the end. Beatrice also shows the theme of love. Her and Benedick have a complex kind of relationship in which they both try to hide their true feelings for each other by always insulting each other at every given opportunity and acting like they hate each other. Although they do love each other, they seem to love the insulting even more; it is their way of showing their love and they seem happier when they are insulting the other.