Prem (Ranbir Kapoor) is a free-loader who, while helping his friend elope, meets Jenny (Katrina Kaif). They both share the trait of developing a stammer when they are emotional. In such a moment, the stammering Jenny induces a spontaneous stammer in Prem, which she misunderstands for mockery. Although this makes her dislike Prem initially, when she finds out his stammer is authentic, the two become friends.