"That's How You Know" is a musical number from the 2007Disney film Enchanted, with music composed by Alan Menken and lyrics by Stephen Schwartz. It is performed by the film's lead actress, Amy Adams, and features the vocals of Marlon Saunders and other singers in the background chorus. The song appears on the soundtrack of Enchanted, which was released on November 20, 2007 in the United States.
In the film, the song is performed by Giselle. During their walk through Central Park, Giselle questions Robert's (Patrick Dempsey) view on love after finding out that he has been with his girlfriend, Nancy (Idina Menzel), for five years and has yet to propose to her. She spontaneously starts to sing in order to explain to him how he should show his affection for Nancy. As Giselle sings and dances through the park, she is joined by other people in the park including buskers, a steelband, elderly dancers, Bavarian dancers, and rollerbladers. They follow her to Bethesda Fountain, where they finish the song. In addition to the aforementioned Disney numbers, "That's How You Know" is played out like big numbers from other musical films such as "Thank You Very Much" from Scrooge and Consider Yourself from Oliver! (the latter also featuring dances from various people including butchers and fishmongers before ending in a flashmob).