There is a suggestion in the text that these “two bears” were once in love with each other (2.1.280-82). Shakespeare does not say why the relationship broke down, but each other is obsessed with and continually talking about the other in a manner which makes it clear that their animosity is a cloak for feelings of a very different kind. That is why they can be tricked with such ease. For all of their gaiety, their scorn of the married state, Beatrice and Benedick are essentially lonely people. They have set themselves up to be imprisoned for life within a set of attitudes and social responses (about the opposite sex, each other, and marriage) which, though witty, are inhibiting and sterile. Neither can break thee self-imposed fetters without help form the outside (the tricks their friends play on them). When this help arrives, they turn joyously to one another with a freedom and depth of engagement lacking in the relationship of Hero and Claudio.
They are equally matched in wit and sharp tongues. They pretend not to be attracted to one another, but secretly, they are intrigued by the strength in the other (we might call this stubbornness or sarcasm) and look forward to the next time they will meet. They enjoy the banter between the two of them, and play tricks with words to see who can come out on top of the "word war". Later on in the play, they realize they are made for one another and begin to date.
Benedick is a bachelor and, will be a bachelor of three score. "Will I never see a Bachelor of three score again" (Translation: "Will I never see a bachelor of sixty-when adults usually died in the times of Much Ado About Nothing.)
Benedick thinks ladies are their to give birth and to do the house work (As a feminist, I strongly oppose this.) Beatrice, like me, think that women are independent and unlike me, they don't need a man.
In their first conversation we see in the play, Beatrice says famiously; "I'd much rather hear my dog, bark at a crow, then hear a man swear that he loves me." And, when Benedick thinks he is going to lose the argument, he ends it briskly; "I am done." Beatrice reacts by simply saying; "You end with the Jade's trick, I know you of old."
They were once In Love but they act as though they hate each other and often battle with strong words?