The women of the play, meaning Hero and Beatrice, teach the men to love by showing them their faults, faults that prohibit real love from thriving.
Through Hero, Claudio learns that he is gullible and has excessive pride. He also learns to feel remorseful about his wrongdoings. All of these lessons are necessary in order for love to thrive. Claudio learns of his gullibility when he learns from Borachio that he has allowed himself to be tricked by both Borachio and Don John into believing that Hero is promiscuous. Due to his gullibility, at Don John's suggestion, he mistakes Margaret in the window for Hero, as we see in his line, "Yet sinned I not / But in mistaking" (V.i.263-264). He also realizes that it was his excessive pride that led him to publicly slander and humiliate Hero, and in pure humility, he begs Leonato to punish him in any way he sees fit and humbly agrees to marry whom Leonato calls his niece.
We especially see the profound remorse that Hero has taught Claudio to feel when he pays his respects to her tomb, hanging an epitaph on her tomb that will "[p]raise her when [he] is dumb," meaning dead (V.iii.10). He even begs the forgiveness of the goddess Diana, a goddess known for her chastity, for killing one of her virgin followers, as we see in his lines, "Pardon, goddess of the night, / Those that slew thy virgin knight" (12-13). In these lines, virgin knight refers to Diana's virgin followers who are warriors that are called virgin knights.
Similarly to Hero, Beatrice also teaches Benedick that he has excessive pride, but she also teaches him to do away with his scornful nature. When we first meet Benedick, he proclaims to hate all women. He is particularly disgusted at the fact that Claudio claims he has fallen in love with Hero, whom Benedick thinks is too short, small, and plain to be considered beautiful, as we see in his lines, "[M]ethinks she's too low for a high praise, too brown for a fair praise, and too little for a great praise" (I.i.147-149). We also learn in this scene just how much Benedick despises and distrusts women, thinking that they are all coquettes and unfaithful, as we see in his lines, "Because I will not do them the wrong to mistrust any, I will do myself the right to trust none" (208-209). However, Beatrice changes all this when he overhears that Beatrice is in love with him. Hearing Claudio, Don Pedro, and Leonato declare how desperately in love Beatrice is and how much Benedick is likely to scorn her or ridicule her, should she tell him, convinces Benedick to amend his ways. Benedick hears how much his friends have "censured" him and decides that he "must not seem proud" (II.iii.205, 208). Hence, while all women are loathsome, suddenly, because he learns he is loved, Beatrice becomes beautiful and wonderful in his eyes and he decides that her love for him "must be requited" (204). Thus, it can be said that Beatrice taught Benedick how to love by teaching him how to relinquish his pride and his scornful feelings.